7-AAD is a fluorescent DNA binding dye that is membrane impermeant and therefore generally excluded from viable cells. The dye is excluded by live cells and early apoptotic cells, but stains necrotic and late apoptotic cells with compromised membrane integrity. 7-AAD/DNA complexes can be excited at 488 nm with an argon-ion laser, and has a large Stokes shift with an emission maxima of 647 nm. 7-AAD intercalates selectively at GC-rich regions of DNA, which makes the dye useful for chromosome banding studies. 7-AAD can be used in multicolor fluorescence microscopy and flow cytometry. The dye has an excitation/emission of 546/647 nm when bound to DNA. Properties: Orange red solid; Store at -20°C, protect from light; Ex/Em= 546/647 nm (with DNA); C62H87N13O16; MW:1270.45; [7240-37-1].