Panorama Ab Microarray Cell Signaling kit: a unique tool for protein expression analysis.

Antibody arrays are a promising new tool for mass analysis of protein level changes in cells responding to different stimuli. Here we describe a novel antibody array system called Panorama Ab Microarray Cell Signaling, that contains 224 antibodies spotted on FAST nitrocellulose-coated slides that can detect protein levels as low as a few nanograms per mL. The antibodies spotted are specific for proteins important in various areas of cell signaling such as phosphorylation, cell cycle, apoptosis, nuclear signaling and cytoskeleton proteins. Furthermore, for some of the protein targes, the Panorama Ab Microarray can detect phosphorylated and nonphosphorylated forms of the traget protein. We found that treatment of the slides post-spotting is important for the array performance (ratio of signal to background) and its stability. Panorama Ab Microarray was used to analyze changes in protein expression in F9 embryonic carcinoma cells stimulated to differentiate by all-trans retinoic acid. We found that the level of several proteins, among them cell cycle regulators and kineases, was either up- or down-regulated. For more than ten protein targets, the results obtained by the Panorama Ab Microarray were confirmed by immunoblotting.