Figure 1.

HPV DNA in plasma of patients with cervical cancer. (A) PCR generating 243-bp DNA fragments of HPV E6 gene (B) Dot-blot hybridization for HPV 18 probe Lanes a1-f1 were positive controls using purified plasmids of HPV type 6, 11, 16, 18, 31 and 33, respectively Lanes a2-f2 were plasma DNA from patients number 4, 106, 148, 161, 183, and 59 respectively Lanes a3-f3 were tumor DNA from the same patients as lanes a2-f2 (C) PCR generating 1392- and 1028-bp DNA fragments of human PIGR genomic sequence and HPV-18 E2 (D) PCR generating 1026, 1028-bp DNA fragments of HPV 16 and 18 E2 gene, respectively, from tumor DNA on a 2% agarose gel stained with ethidium bromide (E) Duplex PCR generating 243- and 177-bp DNA fragments of HPV E6 gene and human ZP3 genomic sequence, respectively From left to right of A, C-E: M, 100-bp ladder standard DNA size marker; - and +, PCR products of the negative control (double-distilled water) and positive control (Hela cell line for A and E; purified plasmids for D; and for C, DNA from human leukocyte for PIGR and purified HPV 18 DNA plasmid for E2 gene), respectively; numbers without p indicate PCR products of tumor DNA; numbers with p indicate PCR products of plasma DNA of CC patients Number 1061p and 1062p were plasma DNA from patient 106 but the samples were collected at different time