7-AAD [7-Aminoactinomycin D] *CAS 7240-37-1*

7-Amino actinomycin D (7-AAD) is a non-permeant dye that can be used to identify non-viable cells. Cells with damaged plasma membranes or with impaired/no cell metabolism are unable to prevent the dye from entering the cell. Once inside the cell, the dyes bind to intracellular DNA producing highly fluorescent adducts which identify the cells as "non-viable". It is widely used in flow cytometry. 7-AAD is excited by the 488 nm laser line of an argon laser with fluorescence detected above 650 nm. Although the emission intensity of 7-AAD is lower than that of PI, the longer wavelength emission may make it more useful for multiplexing assays in combination with other 488 nm-excited fluorochromes such as FITC and PE.