Patent ID: 8034562

Claim:
A method for isolating plasmid DNA from biomass, said method comprising an aqueous 2-phase system having a polymer component and a salt component, said method comprising the steps of: (a) suspending the biomass, (b) adding alkaline lysis buffer and incubating for a sufficient period of time for alkaline lysis of the biomass and formation of an alkaline lysis batch, (c) adding a salt component which neutralizes the lysis buffer and forms the salt component of the 2-phase system, and incubating for a sufficient period of time to neutralize the alkaline lysis batch, (d) combining a first polyethylene glycol component having a first average molecular weight, a second polyethylene glycol component having a different, second average molecular weight, and the neutralized alkaline lysis batch of (c), and mixing, wherein the polymer component of the 2-phase system comprises the first and second polyethylene glycol components, and (e) forming an upper phase containing contaminants and a lower phase containing the plasmid DNA, wherein the suspension of the biomass, the addition of the lysis buffer, salt component and polymer component are all carried out in a single reaction vessel without there being an intermediate centrifugation step.