A quick hydroxyapatite chromatography technique especially adapted for work with DNA networks.

During the renaturation of DNAs large networks build up which cannot be eluted from hydroxyapatite under standard fractionation conditions (60 degrees C, 0.5 M PB). This is a serious problem especially in plant-DNA renaturation studies as hyperpolymers may comprise more than half of the renatured DNA mass even at moderately long initial fragment lengths and low C0t values. Utilizing the acid solubility of hydroxyapatite a method is outlined which will recover the total double-stranded DNA fraction and will prepare the column for the next fractionation in one quick operation. As the method is time saving compared to the standard hydroxyapatite fractionation procedure its general application may prove to be useful.