Copyright information:Taken from "The influence of visible light exposure on cultured RGC-5 cells"Molecular Vision 2007;14():334-344.Published online 11 Feb 2007PMCID:PMC2254956. These experiments were conducted in normal culture medium (A, C) and medium deprived of serum (B, D). Cultures were exposed to light, 1000 lux, for 48 h (C, D) or maintained in the dark (A, B) and processed for the localization of breakdown of DNA (TUNEL). It can be seen that light enhanced the numbers of TUNEL-positive cells (arrows) and this was greatest in serum-free conditions. The scale bar represents a distance of 20 μm. Quantification of several experiments for each condition shown in A-D is shown in E (black bars represent cells incubated with serum, while empty bars indicate cells incubated without serum). Statistical analysis using the one-way ANOVA followed by a post-hoc Bonferroni test and comparing with controls incubated in the dark for the same length of time in the presence of serum (n=10), showed significance levels denoted as follows: *