Each product sample was
dissolved in 25 μL of PCR reaction mixture and heated at 95 °C for
3 min, cooled to 85 °C, and mixed with 5 μL of Taq polymerase solution
(1 unit) that was preheated at 85 °C for 1 min. The thermal cycle was
95 °C, 30 s; 55 °C, 30 s; 72 °C, 45 s for 26 cycles. The PCR products were
applied to non-denaturing polyacrylamide gels. After electrophoresis,
the resulting ladder pattern with 6 base increments was visualized
using ethidium bromide under UV illumination.