Figure 2: Fluorescence (arbitrary units) of the epidermis as a function of time (hours) when a) treated with 20 mg ALA only or 20 mg ALA plus 10 mg CP94, topically or b) untreated (when the opposite flank of the animal had been treated with 20 mg ALA only or 20 mg ALA plus 10 mg CP94, topically). Each point represents the mean (with the standard error of the mean) from two separate animals.