Determination of copy numbers of KSHV in KS-1 cell line. Lane A, 100% KS-1 cell line DNA was amplified with GAPDH primers; lane B, 100% KS-1 cell line DNA; lane C, 100% salmon sperm DNA; lanes D through J, twofold dilutions of KS-1 cell line DNA in salmon sperm DNA, from 1:1 to 1:64. Lanes B through J were amplified with ORF 73 (open reading frame of KSHV) primers. The intensity of the band of GAPDH amplified with 100% KS-1 cell line DNA is close to the intensity of the PCR product of the ORF 73 amplified with a 1:8 dilution of KS-1 cell line DNA. The beta emissions of each band of the membrane were also counted by Ambis 4000; emissions of radioactive lanes A and G were 724 cpm and 750 cpm, respectively.