Amyloglucosidase suppresses interference by glycogen in the quantification of DNA using the Hoechst 33258 dye

摘要

The Hoechst dye fluorescence technique, which is used for the quantitative determination of DNA (12), requires high saline concentrations at neutral pH to reach maximal fluorescence of the DNA-dye complex and to render the DNA fully accessible to the dye by dissociating foreign molecules (3,12). In conventional assays, the DNA is alcohol-precipitated and then resuspended in buffer containing 2 M NaC1 (12). The procedure has been modified for low DNA concentrations (<1 #mu#g/mL) by adding a co-precipitating macromolecule such as glycogen, linear polyacrylamide, tRNA, or spermidine before the alcohol step to improve precipitation and recovery of DNA (8,10). A combination of the co-precipitation and fluorescence techniques is convenient for quantitative DNA determinations in samples containing low DNA concentrations.