Cell viability can be assessed based on various cellular features and mechanisms. These include cell membrane integrity (detected by cell impermeable dyes or leakage of intracellular lactate dehydrogenase (LDH) activity), monitoring of ATP with bioluminescence assays, determining esterase activity with Calcein-AM or Fluorescein-DA, measuring cellular Redox status with MTT, MTS, WST, or XTT, and detecting the mitochondrial membrane potential with JC-1. Various cell viability assays have been developed for plate readers (monitoring absorbance and luminescence), flow cytometry, and image cytometry (e.g. NucleoCounter® NC-3000TM from ChemoMetec); however, none of these assays have been optimized for near-infrared detection with the Odyssey Imaging System. This collection contains protocols to perform the assay with 3 different cell lines:Saponin-treated A431 CellsStaurosporine-treated Jurkat CellsCamptothecin-treated RAW264.7 Cells