The GEArray Q Series Human Endothelial Cell Biology Gene Array is designed for analysis of the expression of genes associated with the major functions of endothelial cells, those being permissibility and vessel tone, angiogenesis, cell activation and adhesion, inflammatory response and apoptosis. Endothelial cells play a very important role in the vasculature system and in the progression of various types of diseases, including those which involve inflammation, atherosclerosis and tumor angiogenesis. SuperArray offers several specific pathway arrays which are very useful tools for studying exactly which genes are involved in certain phenotypes or how cells respond to certain treatments. In our case, we are studying the effect that the anticoagulant and cytoprotective Activated Protein C (APC), in its different forms, has on endothelial cells from different origins.
The arrays come on a nylon membrane with 96 specific cDNAs spotted in quadruplicate together with 4 housekeeping genes and 2 negative controls. The membranes are in small hybridization tubes ready to be re-hydrated and hybridized; the entire procedure should be done in hybridization bottles (bottles which come standard with any hybridization oven will work). The kit provides the Hybridization Solution and the Buffer AF for labeling of specific target RNA. The only thing required is to add salmon sperm DNA in the hybridization.
In our lab, we have been using these arrays for over 3 years and have found them very easy to use. Because the arrays are focused on specific pathways, they are very informative, as all the genes contained on the array will be of interest to the performed study. The manufacturer recommends the use of their probe labeling kit and their detection kit, which makes the whole system effective, although expensive. Using the recommended labeling kit, one can produce biotin-labeled probes for the hybridization of the cDNA arrays. After hybridization, the arrays can be detected using the Chemiluminescent Detection Kit that SuperArray also recommends. The results can be easily analyzed using a digital image reader (we use a system from Fuji) and the raw data can be then further analyzed and converted into a meaningful spreadsheet with the software package that SuperArray provides, allowing for the statistical analysis of the results.
One negative point is that they only provide enough labeling buffer for the exact number of membranes in the kit. The manufacturer says the membranes are single use, but we have been stripping them with SDS and re-probing them up to 2 times with no loss of signal whatsoever. In my opinion, it would be a good idea if the company included additional AF Buffer (or would at least admit that they can be re-probed). Something to watch carefully is the screw top on the tubes as sometimes they can leak.