string: The first-round PCR products were used directly in a second round of PCR using primers 2B and F (Hatada et al., 2010; Shibata et al., 2007; Yoshimura et al., 2006, 2010b) for gp120, IN 2F (59-CTGGCATGGGTACCAGCACACAA-39) and IN 2R (39-CCTAGTGGGATGTGTACTTCTGAACTTA-39) for IN, and IN 2F and F for‚Ä¶