Propidium Iodide

Propidium iodide (PI) is a red-fluorescent nuclear staining dye that binds double-stranded DNA. As a membrane impermeant fluorophore, PI can reach the nucleus only in dead cells with disrupted cell membranes. This selectivity has led to its widespread use as a live-dead cellular stain for analyzing cell viability. PI is commonly used in a variety of cell staining applications, such as flow cytometry, fluorescence microscopy, fluorometry, and confocal laser scanning microscopy and is compatible with other dyes.