Time requirements of alkali vs. NID plasmid minipreps.

Both procedures were performed without rinsing DNA pellets with 70% ethanol. Distriman repetitive pipette (Gilson, Inc., Middleton, WI) was used to dispense solutions. Initiation of next step of procedure was not allowed until ongoing step was completed. The total procedure time was the sum of operational time and the preparation/working equipment times, such as incubators and centrifuges (see Materials and Methods).