Southern blot of transposon insertion mutants of Schu S4 that were defective in intracellular growth in HepG2 cells. Chromosomal DNA from mutants digested with BclI was subjected Southern hybridization with a PCR product amplified from the EZ::TN<rpsLpRparr-2> DNA template. Lanes 1–15 contain DNA from rifampin-resistant mutants of Schu S4. Lane 16 contains wild-type Schu S4 DNA and Lane 17 contains the probe DNA. Each mutant contains a single copy of the transposon.