[9] Alkaline elution versus fluorescence analysis of DNA unwinding

Abstract

Publisher Summary Induction and rejoining of DNA strand breaks in X-irradiated cells may be measured by two methods: alkaline filter elution and fluorometric analysis of DNA unwinding (FADU). The chapter presents a comparison between the two methods and states that the FADU method has proved to be as sensitive as the alkaline filter elution approach in detecting X-ray-induced DNA damage. Even though the generation of free radicals is involved in many metabolic reactions in vivo , free radicals are potentially dangerous for living cells. The issue of risk assessment from exposure to chemicals and from exposure to radiation, both of which produce free radicals (the reactive oxygen species in particular: hydrogen peroxide, superoxide anion, and hydroxyl radicals), centers around oncogenic, mutagenic, and teratogenic effects. Because DNA strand breaks may play an important role in mutagenesis and oncogenesis, the dose–effect relationships and rejoining kinetics are essential indicators reflecting cellular response processes. Apart from primary induced breaks many other DNA lesions may be transformed to strand breaks and can thus easily be measured and quantified. Therefore, it is therefore necessary to have methods that measure DNA strand breaks rapidly and reproducibly.