Microarray analysis of Human Epidermal Keratinocytes, neonatal (HEKn) exposed to solar-simulated visible and ultraviolet radiation with and without sunscreen protection.

Kertinocyte cultures grown in 60 mm petri dishes were placed 186 mm from the solar simulator source (Solar-simulated ultraviolet radiation 1600W Xenon short arc lamp with an Oriel Air Mass 1 Direct Filter, (AM1:D:B; model 81074) and KG2 Short Pass Filter. irradiance 9.84 mW/cm² for UVA (98.3%), 0.174 mW/cm² for UVB (1.7%) and 10 mW/cm² (0.017 mW/cm² erythemally-weighted) for the total UVR irradiance) and received a dose of either 0, 10, 20 and 150 kJ/m2 of unweighted ultraviolet radiation and 0, 10 and 150 kJ/m2 of unweighted ultraviolet radiation with SPF 15 sunscreen filtration (Homosalate 3%, Octisalate 4%, Avobenzone 2%, Titanium dioxide 0.66%) (2 mg/cm2 sandwiched between two 5x5 inch quartz plates) and were temperature controlled at 37oC using a customized water-bath. Six and Twenty-four hours post-exposure cells were harvested and RNA was extracted and subjected to microarray analysis. Expression profiling by array analysis-Sample set, 0, 10, 20 and 150 kJ/m2 of UVR and 0, 10 and 150 kJ/m2 UVR with sunscreen filtration, analysed 6 h and 24 h post exposure, for HEKn cells (n=6).