Generation and PCR Screening of Bacteriophage Sublibraries Enriched for Rare Clones (the Sublibrary Method )

The simple sublibrary method described in this chapter allows the detection and rapid isolation of rare clones from bacteriophage λ libraries. The method is based on the ability of polymerase chain reaction (PCR) to detect clones present in a library at very low frequencies. Clones present at frequencies as low as one in 10,000,000, which would normally be impractical to isolate by conventional probe hybridization, can be rapidly isolated in this way (1 ). The method can also be used to isolate clones that are initially undetectable by PCR in λ libraries.