Measurement of cell proliferation and viability is frequently used in clinical and experimental immunology as means of assessing cell activation in response to diseases, infections and environmental stimulations. Fluoro IndoBlu assay can be used for the measurement of cell proliferation in response to antigens, cytokines, growth factors, and mitogens. It can also be used for the analysis of cytotoxic effects of anticancer drugs, drug resistance, cytotoxic pharmaceutical compounds, and other toxic agents.Staurosporine induced Jurkat cell viability assay. Titrated doses of staurosporine were added into seeded Jurkat (10,000 cells/well) cells in 96 well black opaque tissue culture plates and incubated at 37?C, 10% CO2 for 24h. Fluoro IndoBluTM (1/10 volume) was added into the cultured cells and incubated for 3h and fluorescence was detected at Ex: 530nm and Em: 590nm.PBMC proliferation in response to mitogen Concanavalin A (Con A) stimulation measured by Fluoro IndoBluTM. PBMC at 15,000 cells were cultured for 3 days in the presence of titrated amounts of Con-A and tested for proliferation using the Fluoro IndoBluTM assay. Fluoro IndoBluTM (1/10 volume) was added to the cultured cells and incubated 37?C for 2h. Fluorescence was detected at Ex: 530nm and Em: 590nm.