Cell Sensitivity Assays: Quantitative Detection of Apoptotic Cells In Vitro Using the TUNEL Assay

Flow cytometry allows rapid multi-parameter analyses of individual cells. Cells are illuminated with incident laser light of a specific wavelength. Resultant light-scatter signals and fluorescence-emission signals from fluorochromes contained at the surface of the cell or within it are detected by an array of photomuliplier tubes. For example, fluorochrome-conjugated antibodies and DNA interchelating dyes can be used to acquire information on protein expression and DNA ploidy (via fluorescence signals) together with information on cell size and structure (via light-scatter signals).