Figure 2From: Development of a robust flow cytometry-based pharmacodynamic assay to detect phospho-protein signals for phosphatidylinositol 3-kinase inhibitors in multiple myelomaDevelopment of phospho flow assay. (a). PD response revealed by phospho flow analysis in MM1s cells. Note the peak shift of pS6 on the histogram in the GDC-0941-treated MM1s cells compared to DMSO. Baseline is defined based on isotype staining. (b). Cross-platform comparison between MSD and phospho flow cytometry. iMFI methodology is used to calculate the pS6 signals (c and d). Intra-assay variation studies demonstrate the absolute quantification of pS6 signals (c) and relative quantification (d), highlighting the coefficient of variation (CV). Note that MM1s cells were treated with DMSO or a PI3K pathway inhibitor (tool compound) for 2 hours in the above studies. Data shown (a-d) are representative of at least three independent studies.Back to article page