Abstract: A method of isolating purified plasmid DNA includes the steps of providing cells containing plasmid DNA and lysing the cells with an alkyldimethylphosphine oxide (APO) detergent to produce a mixture, centrifuging the cell and APO mixture, reserving a supernatant containing purified plasmid DNA and isolating the purified plasmid DNA, from the supernatant. Isolation and purification occurs in the absence of hazardous materials such as phenol and chloroform. Prior to mixing, the APO detergent is preferably combined with a strong base to produce a stable solution.

Abstract: Aqueous mixtures of hydrophilic and hydrophobic molecules are separated by adding to the aqueous mixture a second aqueous solution containing 95 mole percent of an alkyldimethylphosphine oxide and 5 mole percent of a phospholipid at 0-10.degree. C. followed by warming to 12-20.degree. C. and separating the resulting two layers.