DNA UVB DOSIMETERS

DNA can be used to establish and monitor solar UVB dose. Since the pri ncipal molecular site of UVB damage in living organisms is DNA, it is logical to quantitate biologically effective solar UVB in DNA dosimete rs. In addition to their particular sensitivity to UVB, DNA dosimeters have the advantages of a 2 pi geometry for collecting diffuse WE radi ation from all vectors, low cost, small size and portability, and no m oving parts. Both molecular (cyclobutane pyrimidine dimers) and biolog ical (bacteriophage plaques) dosimeters can be quantitated as endpoint s to yield the total dose. DNA dosimeters integrate the absorbed energ y of all UVB wavelengths (290-320 nm), are highly sensitive to the dif ferential biological effectiveness of these wavelengths, and also inte grate over time in hours, days or weeks of exposure. Our experiments h ave focused on the demonstration of DNA solar dosimeters in the ocean at various depths, the application of the dosimeters to the terrestria l monitoring of solar UVB under various conditions, and the developmen t of a mini-dosimeter which uses nanograms of DNA and is assayed by po lymerase chain reaction.