[Sorting of living and dead cells by flow cytometry--staining principle and basic experiment].

Simultaneous staining with fluorescein diacetate (FDA) and propidium iodide (PI) is described for use in the identification of living cells and dead cells. FDA passes through living cell membranes and is hydrolyzed by intracellular esterase to produce fluorescein. Fluorescein accumulates inside the cell and emits green. PI passes through dead cell membranes and intercalates with DNA to form a bright red fluorescent complex. Living cells and dead cells are easily identified on the cytograms by flow cytometry. In cases of normal uterine squamous epithelium, white blood cells are viable, while superficial type cells and intermediate type cells are dead.