PCR amplification of IS 26 and IS 26 -associated DNA fragments. (A) Primer design. Symbols of arrow and dashed arrow represent IS26in primers and IS26out primers, respectively. (B) PCR products amplified by IS26in primers. (C) PCR products amplified by IS26out primers. M1: 100-bp size marker. N: negative control. M2: 1-kb size marker.