Finding new biomarkers for diagnosis, prognosis or prediction is a hot area in clinical & translational research. Three recent publications are a good example of this. [Read more…]
The sensitivity and specificity of the primary and secondary antibodies used together with the IHC procedure used, are critical to avoid biased results. Several factors can cause false-positive or false-negative data, so they should all be verified as much as possible for each experimental set-up.
- Detection of the antigen of interest by the primary antibody
- Detection of the primary antibody by secondary antibodies
- Tissue preparation
Here, let’s look at 3 tips that will be of help to improve your IHC data. [Read more…]
Following our series of posts on tumour immunity, I’d like to mention an article published by researchers from the Ben-Gurion University of the Negev (Israel). The authors investigated the negative correlation between caffeine consumption and incidence of tumours. Or to say it more simply, intake of caffeine favours the immune system fighting tumours. (1) [Read more…]
Early in 2015, researchers of The University of Queensland Diamantina Institute (Australia) have shown a very sensible approach to the discovery of new biomarkers associated to transition from non-metastatic tumours to metastatic tumours in osteosarcoma. Not to be a spoiler, but they found that the uPA/uPAR axis is crucial for this, and can be used as a prognostic biomarker. In fact, inhibition of this axis can inhibit the metastasis in this type of tumours. (Endo-Muñoz et al. DOI: 10.1371/journal.pone.0133592).
I don’t want to focus on the biomarker per se, but rather, on the process that this lab followed to discover this new biomarker. [Read more…]
A recent publication by ArrayBridge, Inc., in cooperation with Wayne State University, focuses on monoclonal antibody (mAb) Higher Order Structure Analysis.
The clinical and biological properties of protein-based therapeutics, or biologics, are closely related to their Higher Order Structures (HOS), which in turn can be altered by many physical and chemical conditions. The paper describes a novel technology to monitor changes in mAb HOS – the Protein Conformational Array (PCA) ELISA – which is based on a unique bank of more than 30 well-characterized antibodies enabling the measurement of protein epitope change on the surface of the mAb. [Read more…]
PSA (Prostate Specific Antigen) has been (and still is) the biomarker of choice for the diagnosis and follow up of patients having a Prostate Cancer (PCa). However, even if it has been used for quite some time now, it is not too specific and its levels may be high for other physiological situations, and not only cancer. Therefore, the need for more specific biomarkers for the correct management of PCa patients is mandatory. A recent publication by Heidegger et al. suggests that Eotaxin-1 (CCL11) could be a more specific biomarker. [Read more…]
The outcome of the interaction between Mycobacterium tuberculosis (Mtb) and a macrophage depends on the interplay between host defense and bacterial immune subversion mechanisms. MicroRNAs (miRNAs) critically regulate several host defense pathways, but their role in the Mtb-macrophage interplay remains unclear.
New techniques such as cDNA microarrays have enabled us to analyse global gene expression. However, almost all cell functions are executed by proteins, which cannot be studied simply through DNA and RNA techniques. In fact, experimental analysis clearly shows disparity can exist between the relative expression levels of mRNA and their corresponding proteins (1).
Therefore, analysis of the proteomic profile is critical, especially in processes that rely on secreted proteins (e.g. inflammation). The conventional approach to analysing multiple protein expression levels has been to use 2-D SDS-PAGE coupled with mass spectrometry. However, these methods are slow, expensive, labor-intensive and require specialised equipment. Moreover, these traditional methods of proteomics are not sensitive enough to detect most secreted biomarkers (typically at pg/ml concentrations).
For some years now, antibody arrays have been available to study markers and publish their discoveries in various areas like Immunology, Atherosclerosis, Inflammation, Angiogenesis, Immunoediting and even signaling pathways (ex. phosphorylation, Receptor Tyrosine Kinases…). So far, however, and in spite of the growing demand by researchers working on stem cells, there were no antibody arrays for this area of research, meaning that individual Western Blots had to be performed. But not any more! [Read more…]
Antibody-based techniques are widely used in Life Science laboratories. Antibody purification is often required to raise purity yield of antibody production batches or to reach publication-grade data. In this post, take advantage of some technical tips and troubleshooting points to improve your antibody purification.