Supravital exposure to propidium iodide identifies apoptotic cells in the absence of nucleosomal DNA fragmentation
✍ Scribed by Loris Zamai; Elisabetta Falcieri; Gregary Marhefka; Marco Vitale
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 968 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0196-4763
No coin nor oath required. For personal study only.
✦ Synopsis
By flow cytometry, we have quantitatively evaluated HL-60, MOLT-4, and P815 apoptotic cells induced with camptothecin, staurosporine, and hyperthennia, respectively. Apoptosis was measured by two m e r e n t flow cytometry techniques, using propidium iodide (PI) uptake in permeabilized and nonpermeabilized cells. Apoptosis also has been analyzed by electron microscopy and DNA cleavage by in situ nick translation and DNA gel electrophoresis. We demonstrate that supravital exposure to propidium iodide without prior permeabilization identifies apoptotic cells, and clearly distinguishes them from necrotic cells in all the cases examined. This capability is independent of the nucleosomal (180-200 bp) fragmentation of DNA (which does not take place in MOLT-4 cells), which is the basis for detection of apoptosis both as a "ladder" by DNA gel electrophoresis and as a hypodiploid peak by flow cytometry. Therefore, alterations in membrane permeability, on which PI uptake in living cells is based, allow distinction of apoptotic cells from necrotic and living cells independently of the heterogeneous biochemical patterns involved in programmed cell death, which may or may not lead to DNA oligonucleosomal fragmentation.