Abstract Simultaneous assessment of cell surface phenotypic markers, activation markers such as CD69 and apoptosis related markers such as CD95/FAS can provide deeper understanding of mechanism and impacts of in vitro mitogenic stimulation on immune cell populations.. Kinetic and dose response studies of PBMC’s with different stimulants was performed and followed with novel simplified assays that could assess levels of CD69 and CD95 on T and B cells followed by plate-basedmicrocapillary flow cytometry. Information on the CD4, CD8, CD3,CD19, CD45 expression levels was also obtained. Our results demonstrate that while CD4 expression on CD4 T cells was rapidly downregulated with phorbol myristate acetate or combinations with ionomycin, but was not impacted by PHA treatment. Tracking of CD95 expression levels demonstrate the elevation of CD95 on T and B cells with PHA treatment with no significant loss in CD4 expression levels. Correlation of T celll activation markers and apoptotic markers and expression levels of phenotypic markers would facilitate further elucidation of the mechanism of T cell activation.