Ethidium Homodimer III, also known as EthD-III, is a red fluorescent dead cell stain for bacteria and mammalian cells. It is a cell membrane-impermeant nucleic acid dye that only stains dead cells with damaged cell membranes. Ethidium Homodimer III was developed by Biotium as a superior alternative to Ethidium Homodimer I. The absorption and emission spectra are similar, but EthD-III is 45% brighter. Ethidium Homodimer III is useful for detecting dead bacteria or mammalian cells by fluorescence microscopy or flow cytometry. Properties: Liquid; Store at 4°C, protect from light; Ex/Em= 279, 522/593 nm (with DNA); MW: ~1000.