Live or Dead? Cell Viability Assay Kit *Red/Blue Dual Fluorescence*. Live or Dead? Cell Viability Assay Kit uses two fluorescent indicators: Cellbrite? Orange (Ex/Em = 550/570 nm) for viable cells and a cell-impermeable DNA-binding dye Nuclear Blue? DCS1 (Ex/Em = 360/450 nm) for the cells with compromised membranes. Cells grown in black-wall plates can be stained and quantified in less than two hours. The assay is more robust and accurate than the other viability assays. It can be readily adapted for a wide variety of fluorescence platforms such as microplate assays, fluorescence microscope, and flow cytometry. The kit provides all the essential components with an optimized assay protocol. It is suitable for both proliferating and non-proliferating cells (either suspension or adherent cells).