Figure 1

Fluorescence detection of apoptosis in cultured human coronary artery endothelial cells. Human coronary artery endothelial cells (HCAEC) were incubated with purified TNF-α (1 ng/ml) in serum-free medium. After 20 hours, the culture vessel was centrifuged to retain detached cells and was labeled with propidium iodide (see Materials and Methods). Greyscale image depicts red fluorescence (>590 nm) due to chromatin-bound propidium iodide in ethanol-fixed HCAEC treated with DNAse-free RNAse. Note condensed chromatin in discrete nuclear fragments in apoptotic cells (arrowheads). Arrows depict normal nuclei. Bar = 10 microns.