FLOW CYTOMETRY ANALYSIS OF RADIATION INDUCED APOPTOSIS IN HL 60 CELL LINE

PURPOSE To analyze qualitatitively and quanititatively radiation induced HL 60 apoptosis. METHODS Apoptosis was induced in HL 60 cell line by irradiation. Light microscope,electron microscope, and agarose gel electrophoresis were performed to analyze apoptosis qualitatively. Flow cytometry was used to detect apoptotic cell DNA content and 3′ OH terminal of DNA fragment labeled by FITC dUTP.RESULTS (1)The irradiated HL 60 cell exhibited condensation of the cytoplasm,chromatin condensation,chromosal clumping and margination,and apoptotic body.(2)The apoptotic cell nuclear DNA was degradated with a characteristic “DNA ladder” subjected to electrophores.(3)Radiation induced HL 60 apoptosis showed a time and dose dependented curve with most apparent apoptosis at 6h after irradiation. The induced apoptotic cell percent measured by flow cytometry increased with dose.CONCLUSIONS Flow cytometry is a rapid,simple,sensitive,and specific method to analyze radiation induced apoptosis,however,its cell death must be confirmed by characteristic cell morphology or“DNA ladder”.