A Comparison of Four Frequently Used Assays for Quantitative Determination of DNA

Abstract

Four frequently used DNA determination methods are compared:the diphenylamine colorimetric assay and three fluorescent stain methods, i.e. diaminobenzoic acid diaminophenylindole and bisimidazole (Hoechst 33258). Interference with these assays by thirty-five substances, on different DNA preparations, are examined. The classical diphenylamine method is found to be the most reliable of all, closely. followed by diaminobenzoic acid staining. The remaining two methods, although very sensitive, perform rather poorly.