Isolation and Analysis of Low Molecular Weight DNA Fraction by Electrophoretic and Chromatographic Techniques

Abstract

Summary

A small fraction of DNA characterized by low molecular weight was isolated from the nuclear DNA of rat hepatocytes using electrophoretic and chromatographic techniques. Control experiments excluded the likelihood that this result could be due to enzymatic or chemical damage during nuclear separation and DNA extraction. Using hydroxyapatite chromatography this fraction was separated into two aliquots, one eluted by 0.12 M phosphate buffer and the other with 0.5 M phosphate buffer. The S^o _20,w, as determined by alkaline sucrose gradients, was 0.96 S for the first aliquot and 3.88 S for the second. The single stranded nature of DNA eluted with 0.12 M phosphate buffer was confirmed by the denaturation curve.