DNA Alkaline Elution: Physical Basis of the Elution Process and Validation of this Method as a Screening Procedure to Identify Chemical Carcinogens
The alkaline elution technique, developed by Kohn and coworkers (Kohn and Ewig, 1973; Kohn et al., 1976; Kohn, 1979), provides a sensitive measurement of DNA single-strand size distribution in mammalian cells and represents an advanced alternative to the technique of alkaline sucrose gradient sedimentation. Alkaline elution of DNA from cell lysates allows size measurement of DNA single strands longer than the sizes that can be measured by sedimentation in alkaline sucrose gradients. The elution technique requires relatively simple and not expensive apparatuses, and is less time-consuming in comparison with the latter. Moreover, it gives more repeatable results and is more suitable to assess DNA damage from various tissues following in vivo exposure to DNA interacting agents. In the last few years, this technique has been widely applied by different groups of researchers to the study of various DNA lesions induced by several physical or chemical agents (ranging from carcinogens to antineoplastic agents), and a large series of results have been collected. The aims of this review are: to discuss the physical basis that governs DNA elution, to summarize the possible application of this method, to revise the use of alkaline elution and its reliability in the assessment of DNA fragmentation in various organs of mice and rats following in vivo exposure to chemical agents, and to evaluate critically its role as a screening procedure for carcinogenic compounds.
KeywordsElution Rate Nitroso Compound Hydrazine Derivative Carcinogenic Potency Strand Length
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