About 7-AAD
7-Aminoactinomycin D (7-AAD) is a red-emitting DNA intercalating fluorophore that binds to G-C rich regions of dead cells or cells with compromised membranes. It can be excited by the 488 nm, 532 nm and 561 nm lasers and collected using a 650 nm long-pass filter. 7-AAD has an excitation peak at 546 nm and an emission peak at 647 nm. NucSpot® Far-Red (Biotium) and Sytox AADvanced (Thermo Fisher Scientific) are poplular alternatives to 7-AAD due to reduced spillover characteristics. 7-AAD is primarily used for dead cell staining, as it is excluded from live cells with intact membranes, however due to the dysregulation of plasma membrane charge that happens with apoptosis, 7-AAD often is an indicator of late-stage apoptosis. This dye can be used in Fluorescence Microscopy or Flow Cytometry applications. This is a generic dye that can be found in many supplier's catalogs.