Research Paper Volume 8, Issue 10 pp 2449—2462

Figure 6. Analysis of the expression of p21 and p16 CDK inhibitors in HeLa cells expressing genetically encoded photosensitizers. HeLa cells that express H2B-miniSOG or H2B-tKR were synchronized in S phase, illuminated with blue (465-495 nm, 65 mW/cm², 5 min) or green (540-580 nm, 200 mW/cm², 15 min) light, allowed to recover for the indicated time intervals (0, 6, 24 and 48 hr), and subjected to gene expression analysis using qRT-PCR and WB. Control (“C”) represents the non-illuminated cells. The expression of p21^CIP1 and p16^INK4a was analyzed using EvaGreen-based qRT-PCR. The amplification levels of the cDNA were normalized to the level of the GAPDH cDNA. The results of one representative experiment are shown. WB was performed with an antibody against p21; GAPDH was used as the loading control.