Bacterial DNA Extraction for Polymerase Chain Reaction and Pulsed-Field Gel Electrophoresis

Some polymerase chain reaction (PCR) applications such as gene detection or typing (1 ,2 ) require little purified DNA and may be performed with crude bacterial extracts. Many methods have been described for this procedure (Chapter 6 ). Some of them are straightforward and consist of simply boiling bacterial cells in water. However, PCR results obtained with such preparations may be erratic. The method described in this chapter (adapted from ref. 2 ) works well with Gram-positive bacteria such as staphylococci, enterococci, and Clostridium difficile .