Introduction

Why?

Hockberger et al (1999) suggest that blue light up to 470 nm can have some phototoxic effect on mammalian cells, from 2 to 6 J/cm². In our experiments, we have observed a much higher cell death rate in the cultures exposed for 24h to blue light than in the control. 24h at 20 mW/m² is actually more than 1700 J/cm². To stay on the safe side, and give the cells 6 J/cm² during 4 hours would mean an average of 0.4 mW/cm². How much activation can we get with this rate? Will we have to push it up? What lighting pattern will give best results? To optimize the number of experiments to perform, we have built a simple model to predict the proportion of photoproduct to be expected at every time point when a sample with LovTAP-VP16 when it's illuminated with a time varying light input.