Application of the single‐cell gel‐electrophoresis ("comet") assay to the detection of primary DNA damage in workers of the rubber industry: Comparison of manual and computerized analysis

Abstract

A recent biochemical technique, the alkaline single‐cell microgel‐electrophoresis ("comet") assay, allows the evaluation of damage occurred at the DNA level in individual cells associated with exposure to genotoxic compounds. The extent of DNA damage may be directly evaluated by the use of simple visual techniques. However, the development of computerized image analysis systems specifically devoted to this assay has made possible an easier and more detailed measure. In a biological monitoring approach aimed to assess the genotoxic hazard following rubber processing, peripheral blood leukocytes of 19 male workers from the rubber industry and of age‐matched controls living in the same area were analyzed for the presence of DNA damage using the “comet”; assay. In this paper we report results obtained after a re‐analysis by a computerized system of photomicrographs previously used for the direct manual measurement of comet length. Considering tail parameters such as tail intensity and tail moment, a statistically significant higher extent of DNA damage was demonstrated in exposed subjects, as compared to controls. On the contrary, visual analysis gave negative results.