A VERSATILE FLASH-PHOTOLYSIS APPARATUS

A flash photolysis apparatus and sample cell suitable for photoaffinity labeling experiments are described and compared to a conventional continuous wave source using potassium ferrioxalate actinometry and activation of a model aryl azide photoaffinity label. The flash lamp enclosure is designed to minimize the potential hazards from UV exposure, lamp explosion and electrical shock. The sample cell design with three concentric annular chambers allows for maximum exposure of the sample to the light sources, use of wavelength selecting filter solutions and temperature control. The flash apparatus delivers 10(5) greater photon flux per unit time and activates the model photoaffinity label four times more efficiently (in terms of total photons) than the continuous wave source which results in a total exposure time using the flash source of 2.5 X 10(-6) that needed using the continuous wave source.