SYTOX™ Blue dead cell stain is a simple and quantitative single-step dead-cell indicator for use with violet laser equipped flow cytometers. SYTOX™ Blue dead cell stain is a high-affinity nucleic acid stain that easily penetrates cells with compromised plasma membranes but will not cross uncompromised cell membranes. After brief incubation with SYTOX™ Blue stain, the nucleic acids of dead cells fluoresce bright blue when excited with 405 nm violet laser light. The violet-excited fluorescence emission of SYTOX™ Blue stain permits clear discrimination from probes excited by most other laser lines, facilitating the development of multicolor assays with minimal spectral overlap between signals. SYTOX™ Blue dead cell stain is supplied as a 1 mM solution in dimethylsulfoxide (DMSO) in a unit size of 1 mL.