D-dimer and Cardiovascular Disease

Fibrinogen is the main protein of the blood coagulation system. It consists of two identical subunits that contain three polypeptide chains: alpha, beta and gamma. The process of blood coagulation results in the activation of fibrinogen into fibrin by thrombin and fibrin polymerization. Fibrin clot is then digested by plasmin, and fibrin degradation products of different molecular weights are released into the bloodstream.

D-dimer is one of these fibrinogen degradation products, and is a biomarker for Cardiovascular damage. Therefore, it is widely used in many detection systems in the market, including ELISAs and lateral flow tests.

Clone 8D3, which has been used in many of these detection systems, is nolonger available. So unless you have the hybridoma in your facility, if you were using 8D3, you will have to consider switching to another monoclonal. [Read more…]

Wnt4 and Rspo1 to promote mammary stem cell self-renewal

GTX101085_39995_20150206_WB_B

WNT4 antibody detects WNT4 protein by western blot analysis. Non-transfected (-) and Wnt4-transfected (+, including V5-tag) 293T whole cell extracts (100 μg) were separated by 10% SDS-PAGE, and the membrane was blotted with WNT4 antibody (Cat. No. 210GTX101085) at a dilution of 1:2500. The V5 was used as internal control (Cat. No. 210GTX117997, 1:2500) shown at the bottom panel.

The behavior of adult mammary stem cells (MaSCs) is precisely controlled by the activities of hormones and local factors, though the underlying mechanisms remain obscure. A recent report by Cai et al in Genes & Development illustrates the dynamic interaction between systemic ovarian hormones, Wnt signaling, and the Wnt agonist R-spondin1 (Rspo1) to promote MaSC self-renewal.

In response to estradiol and progesterone, R-spondin1 and Wnt4, but not Wnt7B, act as niche factors to drive MaSC regeneration, with Wnt4 acting through the canonical Wnt/β-catenin signaling pathway. This work establishes a clear mechanistic link between locally acting Wnt signals and the systemic hormone growth response of MaSCs, unveiling the intriguing concept that hormones induce a collaborative local niche environment for stem cells.

Working on unveiling the mechanisms of stem cell fate and differentiation? We’d like to hear from you!

 

5 Tips for Flow Cytometry

Flow cytometry, even if somehow a “classical” technique, is still very valuable in Immunology. Uses of flow cytometry vary from cell identification & sorting based on membrane molecules, characterisation and quantification of secreted and intracellular molecules, as well as, more recently, analysis related to exosomes.

Following our series of technical tips for common experiments in Life Sciences (phospho-WB, secondaries, IF, ELISA, primary cell culture), we present today a series of tips to improve your flow cytometry results. [Read more…]

Which Antibodies for Epigenetics?

The nucleosome core particle is the fundamental structural unit of the eukaryotic genome. It consists of a histone octamer composed of two H2A-H2B dimers and a H3-H4 tetramer wrapped by ~146 base pairs of DNA. A linker histone (i.e., H1) associates with the nucleosomal dyad as well as with linker DNA on either side of the nucleosome, resulting in the formation of the chromatosome. All the core and linker histones are posttranslationally decorated, with at least 160 total modifications described to date including acetylation, methylation, phosphorylation, propionylation, citrullination, formylation, proline isomerization, butyrylation, ADP ribosylation, ubiquitylation, sumoylation, and the more recently identified glycosylation and crotonylation.

These modifications are thought to impact chromatin functions by either altering chromatin packaging or through the recruitment/inhibition of specific chromatin binding factors. Thus, the combined signal from a particular collection of histone marks constitutes a “histone code” that affects gene expression or other chromatin-based functions. [Read more…]

6 popular exosome antibodies !

The Exosome is a protein complex able to degrade the various types of RNA molecules. It can be found in eukaryotes and archaea cells.

Exosomes can be formed by all cell types and in particular lymphocytes, platelets, mast cells, dendritic cells, stem cells, astrocytes or tumor cells.

Exosomes play important roles in coagulation, waste management, and intercellular signaling. They are also used for clinical applications such as therapy, prognosis, and markers for disease. Exosomal marker antibodies detect proteins specific to the exosomes. They can help with the study of the morphology and dynamics of the exosome. A second task for this kind of antibodies is to elucidate the roles a protein may play in a number of tasks that are centered in or influenced by the exosome.

Here are 6 popular antibodies used by researchers!

[Read more…]

Focus on the Calcineurin-NFAT Pathway…

A few weeks ago, I received an email from one of our blog readers. Following my post about the Autophagy pathway, she asked me for the same kind of post about the Calcineurin-NFAT Pathway (Cn-NFAT). With my colleague, Ana (thank you!), we did some research about this pathway and this post is the result. We hope it will help you!

[Read more…]

From RUO to IVD – the acronym guide to reagents’ intended use

Most of us use (and abuse) acronyms in chats and texts. Even in posts. Today, we will have a look at some acronyms used in research, and how they relate to the intended use of reagents. [Read more…]

WB & ELISAs using mAb-treated samples

Biologicals are increasingly being used in therapy, helping to cure thousands of patients, or at least improving their quality of life.

Research continues to move forward in this area, as proved by 7 400 citations in 2014 only when using “biologicals” as a search term, or about 200 citations when using “therapeutic mAb”. Many research groups, especially those working on Oncology, continue to investigate on the mechanism of action of biologicals, specially mAbs, as well as on any possible resistances found in non-responsive patients.

For these mechanistic or functional studies, antibody-based techniques such as ELISAs, antibody arrays, flow cytometry, etc. are routinely performed, using samples from patients being treated with therapeutic mAbs. [Read more…]

Validated antibodies for Ectodermal Stem Cell Lineage

Self-renewal and differentiation capacities into multiple cell-types are 2 main characteristics of Stem Cells. Contrarily to Embryonic Stem Cells, Adult Stem Cells (ASC) are already committed to a differentiated lineage. Nevertheless, ASC still retain capacities of generating various cell types within their restricted lineage. It’s thus crucial to be able to access high quality and reliable research tools when tracking cell differentiation. Here, we’ll review the most popular reagents used to characterize the ectodermal lineage.

[Read more…]

Focus on Organelle Markers…

In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and it is usually separately enclosed within its own lipid bilayer (wikipedia). They are often suspended in the cytosol, or attached to the plasma membrane. Organelles were historically identified through the use of some form of microscopy and by cell fractionation.

[Read more…]