The single-cell gel electrophoresis (SCGE) assay, universally designated as the comet assay, has established itself as a foundational methodology across contemporary molecular toxicology, environmental biomonitoring, and regulatory genetic toxicology. By micro-electrophoretically resolving DNA damage within individual eukaryotic nuclei, the assay delivers exceptional analytical sensitivity, broad compatibility across proliferating and quiescent tissues, and direct visual assessment of cell-to-cell genomic heterogeneity. The alkaline adaptation (pH > 13) provides simultaneous detection of primary DNA single-strand breaks (SSBs), double-strand breaks (DSBs), alkali-labile sites (ALS), and transient enzymatic repair scission intermediates. Furthermore, incorporating lesion-specific repair endonucleases (such as Fpg and hOGG1) enables high-precision quantification of oxidative and alkylative purine/pyrimidine base damage. This comprehensive article details the fundamental biophysical mechanisms governing nucleoid unwinding and electrophoretic fragment migration, provides exhaustive step-by-step experimental optimization criteria, evaluates quantitative scoring metrics (% tail DNA, tail moment, tail length), addresses critical analytical confounders including cytotoxicity-induced hedgehogs, surveys high-throughput miniaturization platforms (12-gel arrays and microfabricated CometChips), and delineates regulatory validation under OECD Test Guideline 489.

Effect of different concentrations of sodium chloride (NaCl) was investigated on Triticum aestivum cultivars WL 711 and PBW 154 along with 8 accessions of Triticum durum. NaCl caused a reduction in root length, shoot length and percentage germination in all cultivars. 200 mM NaCl concentration was found to be more deleterious than 100 mM, for germination in petridishes. In T. durum, the cultivars which performed very poorly in petridishes showed better salt tolerance in soil cultures. Soil cultures with balanced nutrient availability may, therefore, be more suited for experiments on salinity tolerance rather than petridish experiments. No consistent associations were exhibited in the levels of proline and glycine betaine with respect to tolerance to salinity. Sugar content decreased with NaCl treatment in most cultivars. It is suggested that tests with whole plant in soil culture will be a better indicator of salinity tolerance.