PhosphoScan^® Profiling Services

Cell Signaling Technology's (CST) PhosphoScan start-to-finish service includes proprietary sample fractionation, phosphopeptide immunoaffinity purification with CST’s optimized phospho-motif antibodies and identification using LC tandem mass spectrometry, as well as extensive informatic data analysis and follow-up consultation with the customer. Typically sample analysis involves pair-wise comparison of cell lines or tissue with and without chemical or genetic modulator treatment, or normal and disease model comparison.

PhosphoScan Profiling is offered with two methods for quantitative analysis: label-free and SILAC analysis. Label-free quantitative analysis delivers qualitative sample PhosphoSignatures™ (phosphopeptides observed in the sample) and relative quantification of differences (fold-change) in phosphopeptide raw intensity measurements between samples being compared in a PhosphoScan study. SILAC (“stable isotope labeling by amino acids in cell culture”), which can be performed with cell lines, can be combined with PhosphoScan to deliver qualitative sample PhosphoSignatures™ and relative quantification through the intensity ratios of light and heavy isotope pairs.

PhosphoScan Applications

• Target validation – PhosphoScan has been used extensively to discover novel mechanisms of disease by providing a strategy to identify aberrantly activated kinases in any disease model.
• Biomarker discovery – PhosphoScan profiling of lead compound activity has proven to be a successful strategy for discovery and validation of biomarkers of compound activity and disease model sensitivity.
• Patient stratification – PhosphoScan studies combined with CST’s PhosphoSignatures™ knowledge-base enable the correlation of kinase activation status and drug sensitivity, which provides the basis for patient stratification assay development.
• Phospho-specific antibody design – PhosphoScan studies that identify or verify sites of phosphorylation on important drug targets and their substrates are instrumental in the optimal site selection for custom rabbit monoclonal antibody development available from CST.