Abbkine Scientific: 三月 2017

2017年3月31日星期五

Weekly Top Scientific Research Review (27/3/2017 – 31/3/2017)

A new week is coming. Some interesting materials have been waiting for you. Let’s surfing together!

1. LACTB is a tumour suppressor that modulates lipid metabolism and cell state.

Post-mitotic, differentiated cells exhibit a variety of characteristics that contrast with those of actively growing neoplastic cells, such as the expression of cell-cycle inhibitors and differentiation factors. Zuzana Keckesova at Whitehead Institute for Biomedical Research in Cambridge, Massachusetts, USA and his colleagues hypothesized that the gene expression profiles of these differentiated cells could reveal the identities of genes that may function as tumour suppressors. Here they show, using in vitro and in vivo studies in mice and humans, that the mitochondrial protein LACTB potently inhibits the proliferation of breast cancer cells. Its mechanism of action involves alteration of mitochondrial lipid metabolism and differentiation of breast cancer cells. This is achieved, at least in part, through reduction of the levels of mitochondrial phosphatidylserine decarboxylase, which is involved in the synthesis of mitochondrial phosphatidylethanolamine. These observations uncover a novel mitochondrial tumour suppressor and demonstrate a connection between mitochondrial lipid metabolism and the differentiation program of breast cancer cells, thereby revealing a previously undescribed mechanism of tumour suppression.

2. The allosteric inhibitor ABL001 enables dual targeting of BCR–ABL1.

Chronic myeloid leukaemia (CML) is driven by the activity of the BCR–ABL1 fusion oncoprotein. ABL1 kinase inhibitors have improved the clinical outcomes for patients with CML, with over 80% of patients treated with imatinib surviving for more than 10 years. Second-generation ABL1 kinase inhibitors induce more potent molecular responses in both previously untreated and imatinib-resistant patients with CML. Studies in patients with chronic-phase CML have shown that around 50% of patients who achieve and maintain undetectable BCR-ABL1 transcript levels for at least 2 years remain disease-free after the withdrawal of treatment. Here, Andrew A. Wylie at Novartis Institutes for BioMedical Research in Cambridge, Massachusetts, USA and his colleagues characterize ABL001 (asciminib), a potent and selective allosteric ABL1 inhibitor that is undergoing clinical development testing in patients with CML and Philadelphia chromosome-positive (Ph⁺) acute lymphoblastic leukaemia. In contrast to catalytic-site ABL1 kinase inhibitors, ABL001 binds to the myristoyl pocket of ABL1 and induces the formation of an inactive kinase conformation. ABL001 and second-generation catalytic inhibitors have similar cellular potencies but distinct patterns of resistance mutations, with genetic barcoding studies revealing pre-existing clonal populations with no shared resistance between ABL001 and the catalytic inhibitor nilotinib. Consistent with this profile, acquired resistance was observed with single-agent therapy in mice; however, the combination of ABL001 and nilotinib led to complete disease control and eradicated CML xenograft tumours without recurrence after the cessation of treatment.

3. Synergistic drug combinations for cancer identified in a CRISPR screen for pairwise genetic interactions.

Identification of effective combination therapies is critical to address the emergence of drug-resistant cancers, but direct screening of all possible drug combinations is infeasible. Here, Kyuho Han at Stanford University in Stanford, California, USA and his colleagues introduce a CRISPR-based double knockout (CDKO) system that improves the efficiency of combinatorial genetic screening using an effective strategy for cloning and sequencing paired single guide RNA (sgRNA) libraries and a robust statistical scoring method for calculating genetic interactions (GIs) from CRISPR-deleted gene pairs. The team applied CDKO to generate a large-scale human GI map, comprising 490,000 double-sgRNAs directed against 21,321 pairs of drug targets in K562 leukemia cells and identified synthetic lethal drug target pairs for which corresponding drugs exhibit synergistic killing. These included the BCL2L1 and MCL1 combination, which was also effective in imatinib-resistant cells. They further validated this system by identifying known and previously unidentified GIs between modifiers of ricin toxicity. This work provides an effective strategy to screen synergistic drug combinations in high-throughput and a CRISPR-based tool to dissect functional GI networks.

4. GuideScan software for improved single and paired CRISPR guide RNA design.

Alexendar R Perez at Memorial Sloan Kettering Cancer Center in New York, USA and his colleagues present GuideScan software for the design of CRISPR guide RNA libraries that can be used to edit coding and noncoding genomic regions. GuideScan produces high-density sets of guide RNAs (gRNAs) for single- and paired-gRNA genome-wide screens. They also show that the trie data structure of GuideScan enables the design of gRNAs that are more specific than those designed by existing tools.

5. Highly efficient RNA-guided base editing in mouse embryos.

Base editors (BEs) composed of a cytidine deaminase fused to CRISPR-Cas9 convert cytidine to uridine, leading to single-base-pair substitutions in eukaryotic cells. Kyoungmi Kim at Institute for Basic Science in Seoul, Republic of Korea and his colleagues delivered BE mRNA or ribonucleoproteins targeting the Dmd or Tyr gene via electroporation or microinjection into mouse zygotes. F0 mice showed nonsense mutations with an efficiency of 44-57% and allelic frequencies of up to 100%, demonstrating an efficient method to generate mice with targeted point mutations.

2017年3月30日星期四

p53 Monoclonal Antibody Review

p53, also known as Cellular tumor antigen p53 or Tumor suppressor p53, was discovered as a cellular protein associating with the transforming protein of SV40 tumor virus. Experimental evidence has suggested that p53 acts as a negative regulator of cell growth in normal cells. Thus, the inactivation or mutation of p53 may be an essential step in the development of malignancy. Wild-type p53 levels in normal cells and tissues were found to be very low. Mutant p53 polypeptide, however, is often found to be present at high concentrations in mammalian tumors and tumor cell lines.

Abbkine p53 Monoclonal Antibody (Mouse Monoclonal Antibody) was validated in IF, IHC-p and WB to detect endogenous p53 proteins of human samples. Abbkine suggested the starting dilutions are as follows: WB: 1:2000, IHC-p: 1:200, IF: 1:100-200. The antibody gave a positive signal in most human tissue, such as Human colon adenocarcinoma tissue sections as well as some whole cell lysates.

Mutations of the p53 protein have some characteristic features. They exhibit a common mutant structure, which can be recognized by monoclonal antibodies specific for p53 in the mutant conformation. We used Abbkine p53 Monoclonal Antibody staining p53 in human colon adenocarcinoma formalin-fixed paraffin-embedded tissue sections. DAB was used as the chromogen. Positive signal was gotten using the antibody. In view of the good performance of this antibody, I will try to use Abbkine other products.

2017年3月28日星期二

IFKine™ Orange Donkey Anti-Mouse IgG – the launch of a unique secondary antibody by Abbkine Scientific

Wuhan, China. 430074. 28^th March 2017. Chinese Science research company, Abbkine Scientific recently announced the launch of an addition to the IFKine™ antibody family - IFKine™ Orange Donkey Anti-Mouse IgG. The new product like others in the family is sourced from animals, offering high quality secondary antibodies from rabbit, goat and donkey.

The antibody reacts with whole molecule mouse IgG, hence the name IFKine™ Orange Donkey Anti-Mouse IgG. In addition to this, it also reacts with other mouse immunoglobulins. It's cross-reaction with human, rabbit, goat, sheep and guinea pig serum proteins has been specialized minimized to reduce non-specific hybrization. The product however has no reactivity on non-immunoglobulin serum proteins.

The IFKine™ Orange Donkey Anti-Mouse IgG like others in the family are available for antibody-based applications such as Western Blot, Immunohistochemistry, Immunofluorescence, Flow Cytometry and ELISA.

Also referred to replace Cy3 Antibody or Dylight 549 Antibody, the product is available in liquid solution, with a suggested starting dilution that ranges between 1:50 and 1:1,000. The optimal working dilutions are however best determined experimentally by the investigator.

The uniqueness of the IFKine™ staining antibody series stems from its improved brightness, less nonspecific hybridization and background and photo stability. These features put together ensure the best fluorescent performance, with its donkey host making it perfect for use in fluoresce staining, particularly in fluoresce multiple labeling.

The product is best stored at -20°C from date of shipment for maximum of one year and should be shipped in gel pack with blue ice.

-MORE-

About Abbkine Scientific

Abbkine Scientific Co. Ltd is a scientific research company founded in 2012 in the United States. Established by a team of scientists and marketing experts, the company moved its headquarters to China to meet up with the growing demand from the Asia Pacific.

The company has been able to combine cutting edge technology from United States and manufacturing engineering and cost advantages from China to provide innovative, high quality assay kits, recombinant proteins, antibodies and other research tools to accelerate life science fundamental research, drug discovery, amongst others.

2017年3月27日星期一

CD23 Monoclonal Antibody Review

CD23 is a 45kDa glycoprotein, which is present on a subpopulation of freshly isolated peripheral blood and tonsil B cells and strongly expressed on EBV-transformed B lymphoblasts. The CD23 molecule is identical to the low affinity IgE receptor found on B cells. Expression of CD23 has been detected in neoplastic cells from cases of B cell chronic lymphocyctic leukaemia and some cases of centroblastic/centrocytic lymphoma.

Abbkine CD23 Monoclonal Antibody was affinity-purified from mouse ascites by affinity-chromatography using specific immunogen. The antibody detects endogenous CD23 proteins of Human, Mouse and Rat samples. The antibody was verified suitable for IF and IHC-p. Abbkine suggested the starting dilutions are as follows: IF:1:200, IHC-p: 1:200.

I bought Abbkine CD23 Monoclonal Antibody for Immunofluorescence analysis and the sample were human-stomach tissue sections. CD23 Monoclonal Antibody was diluted just according to Abbkine suggestion at 1:200 (4°C, overnight). IFKine™ Orange Donkey Anti-Mouse IgG was diluted at 1:300 (room temperature, 50min). A positive fluorescence result was virtually 100% specific. I have to say this antibody is worth buying.

2017年3月24日星期五

Weekly Top Scientific Research Review (20/3/2017 – 25/3/2017)

This week, we provide materials about temporal mixture modeling resolves T_H1/T_FH fate bifurcation, cancer epigenome, PARP inhibitors, mimicry of HIV neutralizing antibody and pediatric brain tumors treatment. Let’s learn together!

1. Single-cell RNA-seq and computational analysis using temporal mixture modeling resolves T_H1/T_FH fate bifurcation in malaria.

Differentiation of naïve CD4⁺ T cells into functionally distinct T helper (T_H) subsets is crucial for the orchestration of immune responses. Because of extensive heterogeneity and multiple overlapping transcriptional programs in differentiating T cell populations, this process has remained a challenge for systematic dissection in vivo. By using single-cell transcriptomics and computational analysis with a temporal mixtures of Gaussian processes model, termed GPfates, Tapio Lönnberg at European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus in Hinxton, Cambridge, U.K and his colleagues reconstructed the developmental trajectories of T_H1 and T_FH (T follicular helper) cells during blood-stage Plasmodium infection in mice. By tracking clonality using endogenous T cell receptor sequences, the team first demonstrated that T_H1/T_FH bifurcation had occurred at both population and single-clone levels. Next, they identified genes whose expression was associated with T_H1 or T_FH fates and demonstrated a T cell-intrinsic role for Galectin-1 in supporting T_H1 differentiation. They also revealed the close molecular relationship between T_H1 and interleukin-10-producing Tr1 cells in this infection. T_H1 and T_FH fates emerged from a highly proliferative precursor that up-regulated aerobic glycolysis and accelerated cell cycling as cytokine expression began. Dynamic gene expression of chemokine receptors around bifurcation predicted roles for cell-cell interaction in driving T_H1/T_FH fates. In particular, they found that precursor T_H cells were coached toward a T_H1 but not a T_FH fate by inflammatory monocytes. Thus, by integrating genomic and computational approaches, their study has provided two unique resources: a database, www.PlasmoTH.org, which facilitates discovery of novel factors controlling T_H1/T_FH fate commitment, and, more generally, GPfates, a modeling framework for characterizing cell differentiation toward multiple fates.

Read more, please click

http://immunology.sciencemag.org/content/2/9/eaal2192

2. The cancer epigenome: Concepts, challenges, and therapeutic opportunities.

Cancer biology is profoundly influenced by changes in the epigenome. Because the dynamic plasticity of the epigenome lends itself well to therapeutic manipulation, the past few years have witnessed an unprecedented investment in the development, characterization, and translation of targeted epigenetic therapies. In this review, Mark A. Dawson at Cancer Research Division, Peter MacCallum Cancer Centre in Melbourne, VIC, Australia provide a broad context for recent developments that offer a greater understanding of how epigenetic regulators facilitate the initiation, maintenance, and evolution of cancer. He discuss newly developed epigenetic therapies and the cellular and molecular mechanisms that may govern sensitivity and resistance to these agents. He also review the rationale for future combination therapies involving existing and emerging epigenetic drugs.

Read more, please click

http://science.sciencemag.org/content/355/6330/1147

3. PARP inhibitors: Synthetic lethality in the clinic.

PARP inhibitors (PARPi), a cancer therapy targeting poly(ADP-ribose) polymerase, are the first clinically approved drugs designed to exploit synthetic lethality, a genetic concept proposed nearly a century ago. Tumors arising in patients who carry germline mutations in either BRCA1 or BRCA2 are sensitive to PARPi because they have a specific type of DNA repair defect. PARPi also show promising activity in more common cancers that share this repair defect. However, as with other targeted therapies, resistance to PARPi arises in advanced disease. In addition, determining the optimal use of PARPi within drug combination approaches has been challenging. Nevertheless, the preclinical discovery of PARPi synthetic lethality and the route to clinical approval provide interesting lessons for the development of other therapies. Here, Christopher J. Lord at The Cancer Research UK Gene Function Laboratory and Breast Cancer Now Toby Robins Research Centre, The Institute of Cancer Research in London, UK and his colleagues discuss current knowledge of PARP inhibitors and potential ways to maximize their clinical effectiveness.

Read more, please click

http://science.sciencemag.org/content/355/6330/1152

4. Mimicry of an HIV broadly neutralizing antibody epitope with a synthetic glycopeptides.

A goal for an HIV-1 vaccine is to overcome virus variability by inducing broadly neutralizing antibodies (bnAbs). One key target of bnAbs is the glycan-polypeptide at the base of the envelope (Env) third variable loop (V3). S. Munir Alam at Duke Human Vaccine Institute, Duke University School of Medicine in Durham, USA and his colleagues have designed and synthesized a homogeneous minimal immunogen with high-mannose glycans reflective of a native Env V3-glycan bnAb epitope (Man₉-V3). V3-glycan bnAbs bound to Man₉-V3 glycopeptide and native-like gp140 trimers with similar affinities. Fluorophore-labeled Man₉-V3 glycopeptides bound to bnAb memory B cells and were able to be used to isolate a V3-glycan bnAb from an HIV-1-infected individual. In rhesus macaques, immunization with Man₉-V3 induced V3-glycan-targeted antibodies. Thus, the Man₉-V3 glycopeptide closely mimics an HIV-1 V3-glycan bnAb epitope and can be used to isolate V3-glycan bnAbs, the authors suggest.

Read more, please click

http://stm.sciencemag.org/content/9/381/eaai7521

5. Disrupting the CD47-SIRPα anti-phagocytic axis by a humanized anti-CD47 antibody is an efficacious treatment for malignant pediatric brain tumors.

Morbidity and mortality associated with pediatric malignant primary brain tumors remain high in the absence of effective therapies. Macrophage-mediated phagocytosis of tumor cells via blockade of the anti-phagocytic CD47-SIRPα interaction using anti-CD47 antibodies has shown promise in preclinical xenografts of various human malignancies. Sharareh Gholamin at Lucile Packard Children’s Hospital, Stanford University School of Medicine in Stanford, CA, USA and her colleagues demonstrate the effect of a humanized anti-CD47 antibody, Hu5F9-G4, on five aggressive and etiologically distinct pediatric brain tumors: group 3 medulloblastoma (primary and metastatic), atypical teratoid rhabdoid tumor, primitive neuroectodermal tumor, pediatric glioblastoma, and diffuse intrinsic pontine glioma. Hu5F9-G4 demonstrated therapeutic efficacy in vitro and in vivo in patient-derived orthotopic xenograft models. Intraventricular administration of Hu5F9-G4 further enhanced its activity against disseminated medulloblastoma leptomeningeal disease. Notably, Hu5F9-G4 showed minimal activity against normal human neural cells in vitro and in vivo, a phenomenon reiterated in an immunocompetent allograft glioma model. Thus, Hu5F9-G4 is a potentially safe and effective therapeutic agent for managing multiple pediatric central nervous system malignancies, the authors suggest.

Read more, please click

http://stm.sciencemag.org/content/9/381/eaaf2968

2017年3月23日星期四

Abbkine Scientific makes another research breakthrough with the launch of the IFKine™ Green Donkey Anti-Goat IgG

Wuhan, China. 430074. 23^th March 2017. Abbkine made a major breakthrough with the addition of the Green Donkey Anti-Goat IgG to the IFKine™ family of secondary antibodies. The product is one of the secondary antibodies designed by Abbkine to help with scientific research purposes, available conjugated to biotin, enzyme or even fluorophore, to be used in different antibody-based applications.

IFKine™ Green Donkey Anti-Goat IgG is known can be used in different antibody-based applications like Western Blot, Immunohistochemistry, Immunofluorescence, Flow Cytometry and ELISA thanks to its unique features that include being sourced from the donkey. Its reaction with whole molecule goat IgG and light chains of all other goat immunoglobulins also stands it out from the competition.

A cross-reaction with rat, mouse, human, and guinea pig serum proteins that has been reduced to minimize non-specific hybridization is also another unique feature of the Green Donkey Anti-Goat IgG as well as its sisters in the family.

The Green Donkey Anti-Goat IgG comes in a liquid solution and investigators are advised to determine the optimal working dilutions after series of experiments. However, the suggested starting dilution is put between 1:50 and 1:1,000 for most fluorescent applications.

The benefits of this unique fluoresce staining secondary antibodies include improved brightness, photo stability and less nonspecific hybridization and background. Its donkey host also ensures that the antibody can be used in fluoresce staining, especially in fluoresce multiple labeling.

-MORE-

About Abbkine Scientific

2017年3月22日星期三

CD20 Monoclonal Antibody Review

CD20 is an activated-glycosylated phosphoprotein expressed on the surface of all B-cells beginning at the pro-B phase (CD45R+, CD117+) and progressively increasing in concentration until maturity. In humans CD20 is encoded by the MS4A1 gene. CD20 is a 48 kDa intermediate filament protein expressed in mature enterocytes; antibodies to CD20 can be used to study the cellular response to stress. CD20, also called Keratin 21, Cytokeratin 20 or CK20, is another synonym for keratin 20. It has been shown that CD20 plays a role in the microenvironmental interactions of B cells.

Abbkine CD20 Monoclonal Antibody was affinity-purified from mouse ascites by affinity-chromatography using specific immunogen. It detects endogenous CD20 proteins in Human, Mouse and Rat samples. The isotype is Mouse IgG1. The antibody is very suitable for IHC-p. Abbkine suggested the starting dilutions are as follows: IHC-p: 1:200.

Immunohistochemistry can be used to determine the presence of CD20 on cells in histological tissue sections. Because CD20 remains present on the cells of most B-cell neoplasms, and is absent on otherwise similar appearing T-cell neoplasms, it can be very useful in diagnosing conditions such as B-cell lymphomas and leukaemias. My sample is Formalin/PFA-fixed paraffin-embedded human tonsil tissue sections, and I purchased Abbkine CD20 Monoclonal Antibody as primary antibody. The immunohistochemical staining of CD20 was found in the right place, and there was little background. It’s pretty worth enough for me.

2017年3月20日星期一

AMACR Monoclonal Antibody Review

α-methylacyl-CoA racemase (AMACR), an enzyme localized in peroxisomes and mitochondria, is involved in the β-oxidation of branched-chain fatty acids and fatty acid derivatives. AMACR has been reported to be a biomarker for prostate cancer. The expression of AMACR is also related to other types of cancers such as hepatocellular carcinoma, noninvasive bladder cancer, colorectal cancer and gastric adenocarcinoma.

Abbkine AMACR Monoclonal Antibody was affinity-purified from mouse ascites by affinity-chromatography using specific immunogen. The antibody was tested to react with Human, Mouse and Rat Samples. It’s the best choice for customers who plan to do IHC-P or WB. The Isotype is Mouse IgG1. Abbkine suggested the starting dilutions are as follows: WB: 1:1000, IHC-p: 1:200. The antibody detects endogenous AMCAR/P504S proteins.

I used Abbkine AMACR Monoclonal Antibody to detect prostate cancer cell line LNCaP and human hepatoma cell line HepG2 cell lysate in western blot. Western blot results showed that AMACR protein was positive in prostate cancer cell line LNCaP and human hepatoma cell line HepG2 cell lysate which was consistent with published literatures. The antibody worked great. The signal produced was very strong and clear. The success of this test lay the foundation of my future research and also save my time.

2017年3月18日星期六

Abbkine Scientific Company Launches Endotoxin Removal Kit (polymyxin B)

Wuhan, China. 430074. 18^th March 2017. Endotoxin is a membrane component of gram-negative bacteria also known as the lipopolysaccharides (LPS) strongly influence the transfection of DNA into sensitive cultured cells, primary cells. Increased endotoxins level leads to the reduction of transfection efficiencies. A single cell contains about 2 million LPS molecules, during cell lysis, the molecules are released. The work of the endotoxins is to imitate a strong immune response resulting in systemic inflammatory response syndrome or sepsis.

Many commercial endotoxin removal kits are based upon non-affinity chromatography methods such as phase separation or the Ion exchange chromatography. These methods are inefficient at removing contaminated endotoxin residual from advance biotherapy products and they are also expensive and time-consuming.

Polymyxin B that can be used to neutralize the biological activities of endotoxin. Abbkine Scientific Company has come up with a endotoxin removal kit that helps in reducing endotoxin levels by 99% and all protein samples, but at the same time maximizing protein recovery. The resin consists of 4% Agarose cross-linked beads to which the polymyxin B has been coupled.

The PurKine^™ Endotoxin removal kit is designed to achieve quality separation from gravity flow column, and each kit is standardized for high-grade clearance of endotoxins from antibodies, viral vectors and recombinant proteins. The PurKine^™ Endotoxin removal kit enables quick processing of a large number of samples with high solute recovery, negligible hold-up volume, and minimal nonspecific absorption losses. The features and benefits of using endotoxin removal resin or the polymyxin B from PurKine^™ include:

Rapid: the polymyxin B allows multiple purifications. This helps in rapid screening and development methods. It also decreases the time used in every step associated with affinity methods.

Effective: the kits offer a standardized method for endotoxin removal from protein and monoclonal antibodies, meaning it offers high capture efficiency and high reproducibility.

Convenient: the technology used allows minimal manual intervention which makes it ideally suited where price sensitivity and current user requirements demand regeneration of affinity matrix.

Flexibility: different pack sizes and has bulk resin, columns, and complete kits formats.

About Abbkine Scientific

Abbkine Scientific Co., Ltd. was founded by a number of scientists and marketing experts in the field of life science in California, USA in 2012. With growing demands from Asia Pacific, it move its headquarters to China. Combining cutting edge technology from United States with China's manufacturing engineering and cost advantages, we aim to provide innovative, high quality assay kits, recombinant proteins, antibodies and other research tools to accelerate life science fundamental research, drug discovery, etc.

2017年3月16日星期四

Weekly Top Scientific Research Review (11/3/2017-17/3/2017)

This week’s topic are about Early tumour growth, Class IIa HDAC inhibition, Antibody therapy, Neanderthal behaviour and Autophagy. Are you attracted by these interesting discoveries? Don’t wait, let’s browse together!

1. Early tumour growth halted.

Cells that eventually give rise to tumours attract immune cells that help to shield them from the body’s defences. This may be one of the earliest events in tumour formation. Bin Zhao at Zhejiang University in Hangzhou, China, and his colleagues studied liver cancer in mice and found that tumour-initiating cells (TICs) turn on production of Yes-associated protein (YAP). This molecule promotes cell proliferation and attracts immune cells called macrophages, which boost tumour growth. The TICs began doing this at an early stage of tumour growth, when they existed as single cells.

Blocking macrophage recruitment prevented TICs from developing into tumours and caused the immune system to eliminate them rapidly. The team also discovered YAP activation and macrophage recruitment in a small sample of precancerous lesions from human livers, suggesting that similar mechanisms might be involved in some human cancers. Targeting YAP or macrophages could be a therapeutic strategy for liver cancer, the authors suggest.

2. Class IIa HDAC inhibition reduces breast tumours and metastases through antitumour macrophages.

Although the main focus of immuno-oncology has been manipulating the adaptive immune system, harnessing both the innate and adaptive arms of the immune system might produce superior tumour reduction and elimination. Tumour-associated macrophages often have net pro-tumour effects, but their embedded location and their untapped potential provide impetus to discover strategies to turn them against tumours. Strategies that deplete (anti-CSF-1 antibodies and CSF-1R inhibition)or stimulate (agonistic anti-CD40 or inhibitory anti-CD47 antibodies) tumour-associated macrophages have had some success.

Jennifer L. Guerriero at Dana-Farber Cancer Institute in Massachusetts, USA, and her colleagues hypothesized that pharmacologic modulation of macrophage phenotype could produce an anti-tumour effect. The team previously reported that a first-in-class selective class IIa histone deacetylase (HDAC) inhibitor, TMP195, influenced human monocyte responses to the colony-stimulating factors CSF-1 and CSF-2 in vitro. Here, they utilize a macrophage-dependent autochthonous mouse model of breast cancer to demonstrate that in vivo TMP195 treatment alters the tumour microenvironment and reduces tumour burden and pulmonary metastases by modulating macrophage phenotypes. TMP195 induces the recruitment and differentiation of highly phagocytic and stimulatory macrophages within tumours. Furthermore, combining TMP195 with chemotherapy regimens or T-cell checkpoint blockade in this model significantly enhances the durability of tumour reduction. These data introduce class IIa HDAC inhibition as a means to harness the anti-tumour potential of macrophages to enhance cancer therapy.

3. Early antibody therapy can induce long-lasting immunity to SHIV.

Highly potent and broadly neutralizing anti-HIV-1 antibodies (bNAbs) have been used to prevent and treat lentivirus infections in humanized mice, macaques, and humans. In immunotherapy experiments, administration of bNAbs to chronically infected animals transiently suppresses virus replication, which invariably returns to pre-treatment levels and results in progression to clinical disease.

Here, Yoshiaki Nishimura at National Institutes of Health in Maryland, USA, and his colleagues show that early administration of bNAbs in a macaque simian/human immunodeficiency virus (SHIV) model is associated with very low levels of persistent viraemia, which leads to the establishment of T-cell immunity and resultant long-term infection control. Animals challenged with SHIV_AD8-EO by mucosal or intravenous routes received a single 2-week course of two potent passively transferred bNAbs (3BNC117 and 10-1074). Viraemia remained undetectable for 56-177 days, depending on bNAb half-life in vivo. Moreover, in the 13 treated monkeys, plasma virus loads subsequently declined to undetectable levels in 6 controller macaques. Four additional animals maintained their counts of T cells carrying the CD4 antigen (CD4⁺) and very low levels of viraemia persisted for over 2 years. The frequency of cells carrying replication-competent virus was less than 1 per 10⁶ circulating CD4⁺ T cells in the six controller macaques. Infusion of a T-cell-depleting anti-CD8β monoclonal antibody to the controller animals led to a specific decline in levels of CD8⁺ T cells and the rapid reappearance of plasma viraemia. In contrast, macaques treated for 15 weeks with combination anti-retroviral therapy, beginning on day 3 after infection, experienced sustained rebound plasma viraemia when treatment was interrupted. Their results show that passive immunotherapy during acute SHIV infection differs from combination anti-retroviral therapy in that it facilitates the emergence of potent CD8⁺ T-cell immunity able to durably suppress virus replication.

4. Neanderthal behaviour, diet, and disease inferred from ancient DNA in dental calculus.

Recent genomic data have revealed multiple interactions between Neanderthals and modern humans, but there is currently little genetic evidence regarding Neanderthal behaviour, diet, or disease.

Laura S. Weyrich at School of Biological Sciences and The Environment Institute, University of Adelaide in Adelaide, South Australia, and his colleagues described the shotgun-sequencing of ancient DNA from five specimens of Neanderthal calcified dental plaque (calculus) and the characterization of regional differences in Neanderthal ecology. At Spy cave, Belgium, Neanderthal diet was heavily meat based and included woolly rhinoceros and wild sheep (mouflon), characteristic of a steppe environment. In contrast, no meat was detected in the diet of Neanderthals from El Sidrón cave, Spain, and dietary components of mushrooms, pine nuts, and moss reflected forest gathering. Differences in diet were also linked to an overall shift in the oral bacterial community (microbiota) and suggested that meat consumption contributed to substantial variation within Neanderthal microbiota. Evidence for self-medication was detected in an El Sidrón Neanderthal with a dental abscess and a chronic gastrointestinal pathogen (Enterocytozoon bieneusi). Metagenomic data from this individual also contained a nearly complete genome of the archaeal commensal Methanobrevibacter oralis (10.2× depth of coverage)—the oldest draft microbial genome generated to date, at around 48,000 years old. DNA preserved within dental calculus represents a notable source of information about the behaviour and health of ancient hominin specimens, as well as a unique system that is useful for the study of long-term microbial evolution, the authors suggest.

5. Autophagy maintains the metabolism and function of young and old stem cells.

With age, haematopoietic stem cells lose their ability to regenerate the blood system, and promote disease development. Autophagy is associated with health and longevity, and is critical for protecting haematopoietic stem cells from metabolic stress.

Theodore T. Ho at Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California in California, USA, and his colleagues show that loss of autophagy in haematopoietic stem cells causes accumulation of mitochondria and an activated metabolic state, which drives accelerated myeloid differentiation mainly through epigenetic deregulations, and impairs haematopoietic stem-cell self-renewal activity and regenerative potential. Strikingly, most haematopoietic stem cells in aged mice share these altered metabolic and functional features. However, approximately one-third of aged haematopoietic stem cells exhibit high autophagy levels and maintain a low metabolic state with robust long-term regeneration potential similar to healthy young haematopoietic stem cells. Their results demonstrate that autophagy actively suppresses haematopoietic stem-cell metabolism by clearing active, healthy mitochondria to maintain quiescence and stemness, and becomes increasingly necessary with age to preserve the regenerative capacity of old haematopoietic stem cells.

2017年3月15日星期三

CD45 Monoclonal Antibody Review

CD45 is a type I transmembrane protein that interacts directly with antigen receptor complex proteins or activates Src family kinases involved in the regulation of T- and B-cell antigen receptor signaling. CD45 appears to be both a positive and a negative regulator that conducts signals depending on specific stimuli and cell type. Human leukocytes including lymphocytes, eosinophils, monocytes, basophils, and neutrophils express CD45, while erythrocytes and platelets are negative for CD45 expression.

Abbkine CD45 Monoclonal Antibody is produced by immunizing mouse with recombinant protein specific to human CD45 protein. Its applications are WB, IHC-p and IF, with a recommended starting dilution of 1:2000 for WB, 1:200 for IHC-p and IF. The investigator is however advised to determine the optimal working dilutions through experiments. The antibody recognizes endogenous levels of total CD45 protein.

Immunohistochemical analysis of paraffin-embedded Human-lung-cancer tissue using Abbkine CD45 Monoclonal Antibody, it gave a positive signal. I tried the protocol Abbkine suggested. The antibody was diluted at 1:200, incubated with tissue sections at 4°C overnight. Sodium citrate pH 6.0 was used for antibody retrieval (>98°C, 20min). Goat anti-mouse secondary antibody was diluted at 1:200 (room temperature, 30min). Negative control was used by secondary antibody only. Obviously, I got the exact result I hope. It saves a lot of precious time which let my test proceeding under my control.

2017年3月14日星期二

Abbkine Scientific Announces There Newly Improved Antibody Purification Protein A/G Kit

Wuhan, China. 430074. 14^th March 2017. The Abbkine Scientific Company has unveiled its highest quality of Protein A/G Agarose as its premium-quality affinity resin for antibody purification. The Purkine™ Protein A/G Agarose consist of recombinant fusions protein A/G that are covalently immobilized onto high-quality beads of cross-linked 4% Agarose for using in lgG purification applications. Tests confirm that the protein A/G resins exceed or equal popular recombinant Protein A/G from leading suppliers and it does not decrease in performance for at least five repeated use.

These particular antibody purifiers from Abbkine provides the most versatile combination features for high purity purification and high yield of the whole lgG from serum samples. The Agarose beads used have chemical and physical properties that are suitable for many affinity purification systems. In addition to the properties and affinity purification, its high flow properties make protein A/G an excellent option for scaling up.

Abbkine Purkine™ Antibody Purification Protein A/G Kit features and benefits include:

High capacity: contains more than 7mg of human resin lgG per mL.

High performance: the combination between the lgG domains of both protein G and protein A together with the recombinant Protein A/G beads contains four Fc-binding domains making it a more convenient tool for purifying immunoglobins and for investigating.

Cost effective: offers the same performance for at least five repeated uses.

Flexible: you can find it in three different formats of bulk resin, spin column, and complete kits.

Robust: because of its highly cross-linked beads, it has a linear tolerate flow rate of up to 300cm/hour.

Easy to use: available in pre-formulated buffers.

The Protein A/G Purification system is an effective purification affinity of lgG from ascites fluid, serum, cell supernatant and other antibody samples. To minimize nonspecific binding of proteins from recombinant protein A/G, it is chemically modified using the propriety method. It binds well to all lgG subclasses including the human LgG subclasses but does not bind with the lgM, serum albumin or the lgA. The portfolio allows the optimization of solubility, maximum protein yield and stability processe.

Using the latest cutting-edge techniques rather than traditional methods, Abbkine has managed to manufacture a series of unique purifications for development and accessories optimization. Their tools are available for samples with improved productivity of nucleic acids, biomolecules markers, antibodies and fusion proteins that are cost effective and makes the workflow easier.

About Abbkine Scientific

2017年3月13日星期一

Weekly Top Scientific Research Review (3/6/2017-3/10/2017)

1. Pregnancy-Related Immune Adaptation Promotes the Emergence of Highly Virulent H1N1 Influenza Virus Strains in Allogenically Pregnant Mice.

Pregnant women are at high risk for severe influenza disease outcomes, yet insights into the underlying mechanisms are limited. Here, we present models of H1N1 infection in syngenic and allogenic pregnant mice; infection in the latter mirrors the severe course of 2009 pandemic influenza in pregnant women. We found that the anti-viral immune response in the pregnant host was significantly restricted as compared to the non-pregnant host. This included a reduced type I interferon response as well as impaired migration of CD8+ T cells into the lung. The multi-faceted failure to mount an anti-viral response in allogenic pregnant mice resulted in a less stringent selective environment that promoted the emergence of 2009 H1N1 virus variants that specifically counteract type I interferon response and mediate increased viral pathogenicity. These insights underscore the importance of influenza vaccination compliance in pregnant women and may open novel therapeutic avenues.

2. Single-Cell Multiomics: Multiple Measurements from Single Cells.

Single-cell sequencing provides information that is not confounded by genotypic or phenotypic heterogeneity of bulk samples. Sequencing of one molecular type (RNA, methylated DNA or open chromatin) in a single cell, furthermore, provides insights into the cell’s phenotype and links to its genotype. Nevertheless, only by taking measurements of these phenotypes and genotypes from the same single cells can such inferences be made unambiguously. In this review, we survey the first experimental approaches that assay, in parallel, multiple molecular types from the same single cell, before considering the challenges and opportunities afforded by these and future technologies.

3. Pyruvate and Metabolic Flexibility: Illuminating a Path Toward Selective Cancer Therapies.

Dysregulated metabolism is an emerging hallmark of cancer, and there is abundant interest in developing therapies to selectively target these aberrant metabolic phenotypes. Sitting at the decision-point between mitochondrial carbohydrate oxidation and aerobic glycolysis (i.e., the ‘Warburg effect’), the synthesis and consumption of pyruvate is tightly controlled and is often differentially regulated in cancer cells. This review examines recent efforts toward understanding and targeting mitochondrial pyruvate metabolism, and addresses some of the successes, pitfalls, and significant challenges of metabolic therapy to date.

4. Tumor–Host Cell Interactions in Ovarian Cancer: Pathways to Therapy Failure.

Although most ovarian cancer patients are highly responsive to chemotherapy, they frequently present with recurrent metastatic lesions that result in poor overall survival, a situation that has not changed in the last 20 years. This review discusses new insights into the regulation of ovarian cancer chemoresistance with a focus on the emerging role of immune and other host cells. Here, we summarize the complex molecular pathways that regulate the interaction between tumor and host cells, discuss the limitations of current in vitro and in vivo models for translational studies, and present perspectives for the development of innovative therapies

5. Developing Cures: Targeting Ontogenesis in Cancer.

Cancer has long been known to histologically resemble developing embryonic tissue. Since this early observation, a mounting body of evidence suggests that cancer mimics or co-opts developmental processes to facilitate tumor initiation and progression. Programs important in both normal ontogenesis and cancer progression broadly fall into three domains: the lineage commitment of pluripotent stem cells, the appropriation of primordial mechanisms of cell motility and invasion, and the influence of multiple aspects of the microenvironment on the parenchyma. In this review we discuss how derangements in these developmental pathways drive cancer progression with a particular focus on how they have emerged as targets of novel treatment strategies.

6. Contributions of Mammalian Chimeras to Pluripotent Stem Cell Research.

Chimeras are widely acknowledged as the gold standard for assessing stem cell pluripotency, based on their capacity to test donor cell lineage potential in the context of an organized, normally developing tissue. Experimental chimeras provide key insights into mammalian developmental mechanisms and offer a resource for interrogating the fate potential of various pluripotent stem cell states. We highlight the applications and current limitations presented by intra- and inter-species chimeras and consider their future contribution to the stem cell field. Despite the technical and ethical demands of experimental chimeras, including human-interspecies chimeras, they are a provocative resource for achieving regenerative medicine goals.

HSP70 Monoclonal Antibody Review

The HSP70 monoclonal antibody is a unique antibody from popular scientific research company, Abbkine Scientific Company Limited. The research outfit headquartered in China has launched different research products including antibodies and the HSP70 Monoclonal Antibody is another amazing scientific discovery, made to help research scientist carry out their task easier and more effectively.

The product otherwise known as HSPA1 Antibody is unique due to its features and inherent benefits, especially when compared to other products of similar nature. The HSPA1L encodes a 70kDa heat shock protein, a distinct attribute of the product. This is in addition to encoding other heat shock proteins and heat shock protein family A (Hsp70) member 1, helping to stabilize existing proteins against aggregation and also mediating the folding of proteins that are newly translated in the cytosol and in organelles.

HSPA1L is found in the main histocompatibility complex class III region, located in a cluster with two different but closely related genes that also encode isoforms of the 70kDa heat shock protein.

Features of the HSP70 Monoclonal Antibody

The product comes with different features that do not only distinguish from the competition, but make it one of the most sought-after monoclonal antibody in the science research world. Some of these features are listed below.

. The HSP70 is formulated in a liquid solution, ensuring ease of use by science researchers and other such users.

. The product has a 1 mg/ml concentration, making it one of the best in the market.

. The storage buffer is PBS, pH 7.4, containing 0.02% sodium oxide as Preservative and 50% Glycerol, helping to maintain its efficiency.

. The HSP70’s immunogen is synthetic peptide.

. The product has a relatively long life span if stored under recommended conditions. The storage instruction of the HSP70 states that the product can be stable for as much as a year at a temperature of -20°C from the shipment date.

. The HSP70 is easy to recover from storage, with a recommended method of centrifuging the original vial after thawing and prior to removing the cap. Aliquot to avoid repeated freezing and thawing.

. The mouse is the host and the HSP70 reacts with rat, mouse and human.

. Its applications are IF and WB, with a recommended starting dilution of between 1:1000 and 2000 for WB, and 1:100 and 200 or IF. The investigator is however advised to determine the optimal working dilutions through experiments.

. It is monoclonal with Mouse IgG1 isotype.

Pros and Cons of the HSP70

There has been no reported case of cons, defects or unsatisfactory remarks about the antibody. This however does not take away the fact that such situations might arise as time passes, but with the continuous effort of the team at Abbkine, defects are expected to be corrected almost immediately they are spotted.

One of the pros of the HSP70 is its purification, as it was affinity-purified from mouse ascites using specific immunogen to guarantee its safety.

Its relatively long lifespan is another merit of the HSP70 as it can last for as long as one year after the shipment date if stored under proper conditions stated above.

The effective detection of endogenous HSP70 proteins is another advantage of the HSP70.

Conclusion

Abbkine have warned against using the product for clinical or human diagnosis as it was specifically made for research use. The HSP70 monoclonal antibody is one that would greatly benefit the science world and researchers in particular, thanks to its amazing features and benefits.

2017年3月11日星期六

New Anti-β-Tubulin Mouse Monoclonal Antibody (3G6) has been released by Abbkine

Wuhan, China. 430074. 11^th March 2017. The Tubulin belongs to a group of several members of a small family of proteins known as the globular proteins. The globular proteins are the major consistent of microtubules. Alpha-tubulin and beta-tubulin are the two most common members of the tubulin family and together they form microtubules from their dimers. After the dimer is incorporated into microtubule, the GTP bounds to the beta-tubulin that eventually hydrolyzes into GDP along with the microtubule protofilament. Dimers bound to GDP fall apart while those bound to GTP tend to assemble into microtubules. Each of the molecule weight approximately 55kDa.

Antibodies from Beta-tubulin is usually used as a loading control for western blot. It is used to normalize the levels of proteins by checking that the protein loading is the same across the gel. However, the level of B-tubulin is not stable in certain cells, such as adipose tissue. Abbkine offers the best quality anti-β-tubulin mouse monoclonal antibody for WB and IHC-p.

Western blotting accurately measures the change of a specific protein under different circumstances and conditions. There are multiple steps involved during the process, including sample loading, sample preparation, protein transfer, signal detections, electrophoresis, and antibody incubation. In order to accurately interpret the results of western blot experiment, it’s advisable to use quality anti-β-tubulin throughout the loading control process. The same amount of protein sample should be used in each loading lane.

Anti-β-tubulin monoclonal antibody from Abbkine has an optimal working dilution that should be determined by investigators during experiments. We suggest that you start diluting as follows, WB 1:5000 or IHC-p 1:200. Using specific immunogenic and the affinity chromatography method, the antibody was affinity-purified from mouse ascites. They are from the monoclonal clonality and Mouse lgG1 isotope. The Anti-β tubulin monoclonal antibody can be reactive in dog, monkey, chicken, rabbit, rat, insects, and humans and also yeast.

When shipped at -20℃, the anti-β tubulin mouse monoclonal antibody is stable for a year from the shipment date. Aliquot to avoid freezing or melting and in the case of product recovery, centrifuge the original vial prior to removing the cap after melting. This product is best for research use only, the Abbkine Scientific Company is not responsible for any patent infringements or violations.

About Abbkine Scientific

Abbkine Scientific Co., Ltd. was founded by a number of scientists and marketing experts in the field of life science in California, USA in 2012. With growing demands from Asia Pacific, it moves its headquarters to China. Combining cutting edge technology from United States with China's manufacturing engineering and cost advantages, we aim to provide innovative, high quality assay kits, recombinant proteins, antibodies and other research tools to accelerate life science fundamental research, drug discovery, etc.

2017年3月8日星期三

HER2 Monoclonal Antibody Review

The ErbB2 (HER2) proto-oncogene encodes a 185 kDa transmembrane, receptor-like glycoprotein with intrinsic tyrosine kinase activity. Amplification of the ErbB2 gene and overexpression of its product are detected in almost 40% of human breast cancers. ErbB2 is a key therapeutic target in the treatment of breast cancer and other carcinomas and targeting the regulation of ErbB2 degradation by the c-Cbl-regulated proteolytic pathway is one potential therapeutic strategy.

Abbkine HER2 Monoclonal Antibody are produced by immunizing mouse with a synthetic peptide. The isotype of the antibody is mouse IgG1. HER2 Monoclonal Antibody detects endogenous levels of total HER2 protein. The antibody does not cross-react with related kinases. Test confirmed the antibody can applied in WB, IF and IHC-p with Human, Mouse and Rat samples. Abbkine suggested the dilutions are: WB: 1:2000-4000, IHC: 1:200 and IF 1:200.

I purchased Abbkine HER2 Monoclonal Antibody for immunofluorescence analysis of Rat-spleen tissue. I dilute the antibody according to the recommendation which is 1:200 for 4°C, overnight. Cy3 labled secondary antibody was diluted at 1:300 at room temperature for 50min. I show my picture in the left . I am very satisfied with this product-high quality research product with affordable price.

2017年3月7日星期二

AbbKine Scientific Releases a New Antibody Purification Protein A Kit

Wuhan, China. 430074. 7^th March 2017. Rather than using the same traditional method that other purifier companies commonly use, PurKine^TMis taking advantage of the latest technology and the latest synthetic process to optimize the development of resin and accessories. PurKine Antibody purification involves isolation of polyclonal antibody, ascites fluids or monoclonal antibody. Recombinant protein A can be scaled for Bioprocess application.

PurKine Antibody Purification Kit can be applied in gravity column procedures on a variable scale as it is immobilized in lgG purification. The PurKine^TM protein A antibody purification kit incorporates Protein A resin that is pre-packed and plugs into ready to use columns. The objective of the purifier is to offer total protein purification solutions. The use of protein A in widespread and has superseded the use of antibodies purification_.

Protein A purification system from Abbkine is designed as a one-step purification that make it easy for research use. The protein A contains high-affinity binding sets that are in four sites that are capable of interacting with Fc region of several species. The essence of affinity utilizes the concept of bio-specificity. This implies that there is an interaction between a natural ligand and a natural binding site, whether it’s protein A antibody interactions.

PurKine^TM offers a wide selection of purifying antibodies using protein A antibody purification. The portfolio is designed to meets screening and Bioprocess needs. The features include

High performance: these resins are designed to maximize the protein yield.

Cost-effective: the pricing is similar or better, but it doesn’t reduce its performance at least for five repeated use.

Flexible: it is available in three different formats including, bulk, spin, and complete kits.

Easy to use: it is pre-formulated for use.

The PurKine^TM Protein A purification product is not for use by humans or clinical diagnosis. They are recommended for research.

About Abbkine Scientific

Galectin-3 Monoclonal Antibody Review

Galectins are a family of β-galactose binding proteins. Galectin-3/LGALS3 is involved in several diverse biological functions. Galectin-3/LGALS3 binds IgE. Galectin-3/LGALS3 production has been shown to increase during inflammation and in obesity, and the protein itself can have an inflammatory effect under certain conditions. Galectin-3/LGALS3 forms a complex with α3, β1 integrin to act as a surface receptor on endothelial cells for the NG2 proteoglycan, which triggers cell motility and angiogenesis. In addition to these functions, galectin-3/LGALS3 is also a required factor for the terminal differentiation of epithelial cells.

Abbkine Galectin-3 Monoclonal Antibody was affinity-purified from mouse ascites by affinity-chromatography using specific immunogen. The antibody recognizes endogenous levels of total galectin-3/LGALS3 protein of human samples, and it’s suitable for IHC-p and WB. Abbkine suggested the starting dilutions are as follows: WB: 1:2000, IHC-p: 1:200. But optimal working dilutions should be determined experimentally by the investigator.

I used Abbkine Galectin-3 Monoclonal Antibody staining Galectin 3 of Human ovarian carcinoma tissue by IHC-p. After antigen retrieval and tissue block, tissue sections were incubated with the Galectin-3 monoclonal antibody (1:200) overnight at 4℃. The antibody performance well. Target proteins are found in which they locate. This antibody is deserved to recommended.

2017年3月5日星期日

The Nobel Prize in Physiology or Medicine 1901

Emil Adolf von Behring

Born: 15 March 1854, Hansdorf (now Lawice), Prussia (now Poland)

Died: 31 March 1917, Marburg, Germany

Affiliation at the time of the award: Marburg University, Marburg, Germany

Prize motivation: “for his work on serum therapy, especially its application against diphtheria, by which he has opened a new road in the domain of medical science

and thereby placed in the hands of the physician a victorious weapon against illness and deaths”

Field: bacteriology, immunity

Work: Many diseases are caused by microorganisms, but the body can use its immune system to defend itself against attacks and become immune to new attacks. As part of its defenses, the immune system forms antibodies that neutralize poisons, or toxins, that are formed by bacteria. Emil von Behring and other researchers showed that by means of blood plasma, or serum, antibodies could be transferred from one person or animal to another person, who also then became immune. In 1900 Emil von Behring introduced serum from immune horses as a method to cure and prevent diphtheria. Emil von Behring – Facts.

2017年3月4日星期六

Scientists create artificial mouse 'embryo' from stem cells for first time

Scientists at the University of Cambridge have managed to create a structure resembling a mouse embryo in culture, using two types of stem cells — the body’s ‘master cells’ — and a 3D scaffold on which they can grow.

Understanding the very early stages of embryo development is of interest because this knowledge may help explain why more than two out of three human pregnancies fail at this time.

Once a mammalian egg has been fertilised by a sperm, it divides multiple times to generate a small, free-floating ball of stem cells. The particular stem cells that will eventually make the future body, the embryonic stem cells (ESCs) cluster together inside the embryo towards one end: this stage of development is known as the blastocyst. The other two types of stem cell in the blastocyst are the extra-embryonic trophoblast stem cells (TSCs), which will form the placenta; and primitive endoderm stem cells that will form the so-called yolk sac, ensuring that the fetus’s organs develop properly and providing essential nutrients.

Previous attempts to grow embryo-like structures using only ESCs have had limited success. This is because early embryo development requires the different types of cell to coordinate closely with each other.
However, in a study published today in the journal Science, Cambridge researchers describe how, using a combination of genetically-modified mouse ESCs and TSCs, together with a 3D scaffold known as an extracellular matrix, they were able to grow a structure capable of assembling itself and whose development and architecture very closely resembled the natural embryo.

“Both the embryonic and extra-embryonic cells start to talk to each other and become organised into a structure that looks like and behaves like an embryo,” explains Professor Magdalena Zernicka-Goetz from the Department of Physiology, Development and Neuroscience, who led the research. “It has anatomically correct regions that develop in the right place and at the right time.”

Professor Zernicka-Goetz and colleagues found a remarkable degree of communication between the two types of stem cell: in a sense, the cells are telling each other where in the embryo to place themselves.

“We knew that interactions between the different types of stem cell are important for development, but the striking thing that our new work illustrates is that this is a real partnership — these cells truly guide each other,” she says. “Without this partnership, the correct development of shape and form and the timely activity of key biological mechanisms doesn’t take place properly.”

Comparing their artificial ’embryo’ to a normally-developing embryo, the team was able to show that its development followed the same pattern of development. The stem cells organise themselves, with ESCs at one end and TSCs at the other. A cavity opens then up within each cluster before joining together, eventually to become the large, so-called pro-amniotic cavity in which the embryo will develop.

While this artificial embryo closely resembles the real thing, it is unlikely that it would develop further into a healthy fetus, say the researchers. To do so, it would likely need the third form of stem cell, which would allow the development of the yolk sac, which provides nourishment for the embryo and within which a network of blood vessel develops. In addition, the system has not been optimised for the correct development of the placenta.

Professor Zernicka-Goetz recently developed a technique that allows blastocysts to develop in vitro beyond the implantation stage, enabling researchers to analyse for the first time key stages of human embryo development up to 13 days after fertilisation. She believes that this latest development could help them overcome one of the main barriers to human embryo research: a shortage of embryos. Currently, embryos are developed from eggs donated through IVF clinics.

“We think that it will be possible to mimic a lot of the developmental events occurring before 14 days using human embryonic and extra-embryonic stem cells using a similar approach to our technique using mouse stem cells,” she says. “We are very optimistic that this will allow us to study key events of this critical stage of human development without actually having to work on embryos. Knowing how development normally occurs will allow us to understand why it so often goes wrong.”

The research was largely funded by the Wellcome Trust and the European Research Council.

Dr Andrew Chisholm, Head of Cellular and Developmental Science at Wellcome, said: “This is an elegant study creating a mouse embryo in culture that gives us a glimpse into the very earliest stages of mammalian development. Professor Zernicka-Goetz’s work really shows the importance of basic research in helping us to solve difficult problems for which we don’t have enough evidence for yet. In theory, similar approaches could one day be used to explore early human development, shedding light on the role of the maternal environment in birth defects and health.”

2017年3月3日星期五

Bcl-2 Monoclonal Antibody Review

Bcl-2 exerts a survival function in response to a wide range of apoptotic stimuli through inhibition of mitochondrial cytochrome c release. It has been implicated in modulating mitochondrial calcium homeostasis and proton flux. BCL2 mutations found in non-Hodgkin lymphomas carrying the chromosomal translocation could be attributed to the Ig somatic hypermutation mechanism resulting in nucleotide transitions.

Abbkine Bcl-2 Monoclonal Antibody was affinity-purified from mouse ascites by affinity-chromatography using specific immunogen. The antibody detects endogenous total Bcl-2 proteins of Human, Mouse and Rat samples. Tested applications of this antibody include WB and IHC-p. Abbkine suggested the starting dilutions are as follows: WB: 1:1000~2000, IHC-p: 1:200.

I used Abbkine Bcl-2 Monoclonal Antibody for WB at 1/1000 dilution. The detected band is approximately 26 kDa which was the same as the predicted molecular weight. I am very satisfied with Abbkine’s product and found it to be worth the cost. I give them a high recommendation and plan to use them again.

2017年3月1日星期三

PurKine™ Biotin-Tag Protein Purification Kit (Streptavidin) – another groundbreaking discovery from Abbkine

Wuhan, China. 430074. 1^st March 2017. Abbkine Scientific Co. Limited recently announced the release of its new product - PurKine™ Biotin-Tag Protein Purification Kit (Streptavidin), otherwise known as Streptavidin or Streptavidin resin. The Biotin resin kit comprises of PurKine™ Biotin-Tag Streptavidin Packed Column 6FF, Binding/Wash Buffer (10X) and Elution buffer (10x).

PurKine Biotin-Tag Protein Purification Kit also referred to as Streptavidin resin, is a product of innovation and ingenuity, made to ease the process of purifying biotin and biotinylated substances. The Biotin tag resin can be used to purify samples from substances like Biotinylated antibodies, proteins, peptides, nucleic acids and other molecules or interaction complexes.

PurKine Biotin-Tag Protein Purification Kit is also useful for capturing, immunoprecipitation and removal of biotinylated antibodies, proteins, peptides, nucleic acids and other molecules or interaction complexes from samples.

The resin, available in prepacked spin column and kit formats is also great for the optimization of the process for maximum protein yield, stability, and solubility, with series of tests confirming no decrease in its performance after several repeated tests.

The resin is robust; with highly crosslinked beads that allow the linear flow rates of up to 500 cm/hour. Its other features and benefits include high capacity with 1 to 3 mg of biotinylated BSA per mL of resin.More than 120 nmol Biotin per mL of resin, high performance, cost-effectiveness, flexibility and ease of use.

It can be stored for as long as a year at a stable temperature of 2-8°C from the shipment date, in blue ice.

About Abbkine Scientific

p53 (Acetyl Lys382) Polyclonal Antibody Review

The p53 tumor suppressor protein plays a major role in cellular response to DNA damage and other genomic aberrations. Activation of p53 can lead to either cell cycle arrest and DNA repair or apoptosis . Acetylation appears to play a positive role in the accumulation of p53 protein in stress response . Following DNA damage, human p53 becomes acetylated at Lys382 (Lys379 in mouse) in vivo to enhance p53-DNA binding.

Abbkine p53 (Acetyl Lys382) Polyclonal Antibody are produced by immunizing Rabbits with a synthetic acetylated peptide corresponding to residues surrounding Lys382 of human p53. The antibody detects endogenous levels of human p53 only when acetylated at lysine 382 and suitable for WB, IHC-p, ELISA.

Abbkine p53 (Acetyl Lys382) Polyclonal Antibody is used to stain human breast adenocarcinoma formalin fixed paraffin embedded tissue sections, 10μg/ml working concentration, for 15 mins at room temperature and detected using an HRP conjugated secondary antibody. The target staining is very clear and the sensitivity of the antibody was perfect.

订阅：博文 (Atom)