text: The most common method is alkaline lysis, which involves the use of a high concentration of a basic solution, such as sodium hydroxide, to lyse the bacterial cells. When bacteria are lysed under alkaline conditions (pH 12.0–12.5) both chromosomal DNA and protein are denatured; the plasmid DNA however, remains stable. Some scientists reduce the concentration of NaOH used to 0.1M in order to reduce the occurrence of ssDNA. After the addition of acetate-containing neutralization buffer  to lower the pH to around 7, the large and less supercoiled chromosomal DNA and proteins  form large complexes and precipitate; but the small bacterial DNA plasmids stay in solution.