Figure 6. An enzyme-linked immunosorbent assay (ELISA) was used to examine the death of the human amniotic fluid (HAF)–treated retinal pigment epithelium (RPE) cultures. Bar graphs showing the apoptotic status of human RPE cells treated with 10%, 20%, or 30% (v/v) HAF compared with 10% (v/v) FBS. The human RPE cells were first incubated for 24 h in serum - or AF–containing media, and the cell death assay was performed according to the instructions accompanying the cell death detection ELISA kits. Positive control was the cytoplasmic histone-associated DNA fragments in a solution supplied in the kit contents. Each bar represents the mean±standard error of the mean (SEM) of two independent experiments in at least triplicate.