Preparation of Crude Extract by Alkaline Lysis.
Alkaline lysis is probably the most generally useful plasmid preparation procedure.
It is fairly rapid, very reliable, and yields reasonably clean crude DNA that can be further purified by any of the purification methods described in this unit. Make this up immediately before use. Do not save any leftover solution. To increase yields, maximize aeration using a flask with a high surface area, add baffles, and shake at approx. Alternatively, treat cultures of cells growing logarithmically with chloramphenicol to amplify the plasmids.