ABSTRACT
Genotoxicity is the potential of a physical or chemical agent to alter genetic information of infectious particles, cells, or individuals. The deoxyribonucleic acid (DNA) unwinding/hydroxylapatite (HAP) batch elution assay has been recently applied on a large scale to field and laboratory studies on genotoxicity in fish embryos, where investigations of DNA damage are still rare. Tissue or hemolymph samples have been prepared too slowly and insufficiently cooled: perform initial steps steadily and completely on ice to minimize activities of endogenous nucleases. DNA damage in fish embryos can be investigated by an alkaline DNA unwinding/HAP batch elution, which provides a sum parameter for a wide spectrum of lesions with sensitivity to alkaline conditions. Laboratory studies with fish embryos in a sunshine simulation apparatus do not cause UV-related DNA damage, which is detectable by the applied assay. Transcription related topoisomerase-like cleavages occur in high densities in sea urchin embryos and vary with developmental stages.
