Figure 1.

Polymerase chain reaction amplification and direct sequencing analysis of hepatitis B virus X region. A: Location of primer set for the nested PCR direct sequencing (1^st primer set; X-pro-F1 and X-pro-R1, 2^nd primer set; X-pro-F2 and X-pro-R2) and Fok-I based nested PRA (1^st primer set; X-pro-F1 and X-pro-R1, 2^nd primer set; X-pro-F2 and X-pro-R3) for the detection of HBxAg V5M mutations and the 3 polymorphisms [V5(GTG), M5(ATG), and L5(CTG or TTG)] of the 5^th codon of HBxAg; B: The amino acid and nucleotide sequences of the X region from six reference strains (Genotype A, B, C1, C2, and D) and 10 chronic hepatitis patients (five carriers and five HCC patients) were aligned.