Suprim Tha Answered Oct 15, 2017
Tribhuwan University
That's because during the renaturation step ie, during addition of solution III (Pot. acetate solution), smaller plasmid DNA renatures fast but long chromosomal DNA cannot. Also these single stranded DNAs along with other residual protein parts due to hydrophobic interactions coagulate to form a white precipate which is pelleted out after this step.