7-AAD

7-AAD is a non-permeable DNA dye for flow cytometry, distinguishing live and dead cells with strong 488 nm fluorescence and minimal spectral overlap.

7-Aminoactinomycin D (7-AAD) is a nucleic acid dye that emits strong fluorescence upon binding to DNA. Its fluorescence properties are similar to those of PI and can be excited by a 488 nm argon-ion laser. However, its emission spectrum is narrower and its wavelength is longer than that of PI, resulting in less interference with other detection channels. It is an excellent alternative to PI in multicolor fluorescence analysis. In addition, 7-AAD is a non-permeable fluorescent dye. While it cannot penetrate the cell membranes of living cells, it can penetrate the membranes of membrane-damaged cells, such as late-stage apoptotic or necrotic cells, and bind to the DNA within them. This allows it to distinguish live cells from necrotic or late-stage apoptotic cells and is commonly used in flow cytometry.

7-AAD is used for DNA analysis and dead cell discrimination, as a viability probe for nonviable cell exclusion, and is excluded by intact cells.