Nested PCR analysis for KSHV sequences from DNA of urogenital specimens from Italian and American individuals. Lane 1, 100-base pair (bp) molecular weight ladder. Lane 2, 0.01% KS-1 cell line DNA diluted in K562 DNA served as a positive control. The 160-bp band represents the nest-primer product; the two upper bands represent fragments derived from the internal and external primer sets. Lane 3, 100% K562 DNA served as a negative control. Lanes 4 through 13 were DNA samples from normal prostate tissue from Italian men. Lanes 14 through 20 were DNA samples from normal prostate tissue from patients from the United States.