Plasmid Miniprep

Plasmid Miniprep This procedure is used to extract plasmid DNA from bacterial cell suspensions and is based on the alkaline lysis procedure developed by Birnboim and Doly (Nucleic Acids Research 7:1513, 1979). The procedure takes advantage of the fact that plasmids are relatively small supercoiled DNA molecules and bacterial chromosomal DNA is much larger and less supercoiled. This difference in topology allows for selective precipitation of the chromosomal DNA and cellular proteins from plasmids and RNA molecules. …

…EDTA. The EDTA will chelate magnesium ions which are a cofactor for most nucleases (enzymes which degrade nucleic acids). If your DNA prep becomes contaminated with a nuclease (like the ones produced by the cells in your skin) then the nuclease will be inactivated by the fact that the magnesium cofactor is unavailable in the solution (because it is chelated by the EDTA). 19. Pool the two 20 uL solutions into one labeled tube. Store in freezer.