Fluorometric quantitation of single-stranded DNA: a method applicable to the technique of alkaline elution

The use of Hoechst dye 33258 for the fluorometric quantitation of single-stranded DNA was investigated for the purpose of developing a simple nonradiometric method of quantitating DNA in fractions collected during the analysis of DNA damage by the method of alkaline elution. The sensitivity of the assay allowed amounts of single-stranded DNA as small as 100 ng to be quantitated reliably. The requirement of a near-neutral pH necessitated that alkaline samples be buffered in order to perform DNA quantitation. However, that the addition of a predetermined volume of buffered dye solution to each sample is the only manipulation required prior to fluorescence measurement makes this procedure the simplest yet described for quantitating DNA collected during alkaline elution.