With the  Plasmid method, the pelleted bacteria are resuspended
(Buffer A1) and plasmid DNA is liberated from the E. coli host cells by SDS / alkaline lysis (Buffer A2). Buffer A3 neutralizes the resulting lysate and creates appropriate conditions for binding of plasmid DNA to the silica membrane of the Plasmid Column. Precipitated protein, genomic DNA, and cell debris are then pelleted by a centrifugation step. The supernatant is loaded onto a  Plasmid  Column.