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!