3.1.3. Insertions 1 (i1) and 2 (i2) can be detected by PCRs T3 and T4
The discrimination of types 1 and 2 can be further enhanced using
primers to detect i1 and i2 found only in type 2 IncC plasmids. Primers
RH1492 and RH1493 (PCR T3) detect a characteristic 428 bp backbone
insertion (i1) in type 2 IncC. The reaction yielded an amplicon of
265 bp from pRMH760 and pDGO100 (type 1), which lack i1, and
693 bp from pSRC119-A/C (type 2) which includes it. Primers RH1494
and RH1495 (PCR T4) were designed to detect the 462 bp i2 backbone
insertion in type 2. The reaction yielded an amplicon of 388 bp from
the type 1 plasmids (pRMH760 and pDGO100), and 850 bp from type
2 (pSR119-A/C).