Alternatively, treat cultures of cells growing logarithmically with chloramphenicol to amplify the plasmids. Growing the bacteria in medium that supports higher cell densities also increases the yield. Most plasmids commonly used today, particularly derivatives of the pUC series, grow at a copy number high enough to routinely yield 1 to 5 mg plasmid DNA from a 500-ml culture grown in LB medium. Put about 10-20 mls of bleach into the empty flasks to kill the bacteria. Let them react with the bleach until color changes.
Bacteria are now safe to pour down the drain with lots of water.
We use the opaque polypropylene Oak Ridge tubes with the Nalgene caps or the polycarbonate tubes with the black caps. Record the volumes of bacterial culture you begin with. The volume of culture can be higher or lower. You should adjust the amounts accordingly. We have a calculating spreadsheet for alkaline lysis on Cell Central.