Propidium iodide is a fluorescent stain for nucleic acids. Cell membrane integrity excludes propidium iodide from staining viable and apoptotic cells. Propidium iodide may be used in flow cytometry to evaluate cell viability when used with other dyes that stain viable cells or cells that are early in the apoptosis process.

This Thermo Scientific Chemicals brand product was originally part of the Alfa Aesar product portfolio. Some documentation and label information may refer to the legacy brand. The original Alfa Aesar product / item code or SKU reference has not changed as a part of the brand transition to Thermo Scientific Chemicals.