Dansyl Chloride: Relative Effect of Patch Testing Time

Dansyl chloride, which fluoresces when illuminated by long-wave ultraviolet (UV) light, and which binds avidly with amino groups, has become an increasingly useful tool in the study of cutaneous function and cutaneous toxicology. A group of 36 human subjects were patched on the inner aspect of their forearms with dansyl chloride for periods, including 12, 15, and 24 hr. The 15-hr patching period was found equivalent to the 24-hr period; the 12-hr patching period results were almost equivalent to those at 15 hr. Shortening patching periods can expand the potential subject population.