PCR analysis of high-molecular-weight DNA extracted from lymphoma tissues of infected monkeys. Primers and probes amplifyinggag (A) and env (B) regions of the SIV genome were used as described in Materials and Methods. Lanes 1 through 5 are samples of monkeys 4, 208, OD5, 8503, and S1, respectively. DNA samples derived from SIV chronically infected HUT 78 cells (lane 6) or HUT 78 uninfected (lane 7) cells were included as positive or negative control, respectively.