Test of QC cloning performed with or without heat inactivation. ( A ) PCR product amplified from G-tailed cDNA prepared from biopsy sample T019 using primers bap2 pc and GC3F. ( B ) Structure of the vector and of the PCR product. ( C , D ) The PCR product was cloned into pICH31480 using T4 DNA polymerase treatment for 5 minutes at 25°C (A, adaptor; U, unknown sequence; K, known sequence; CS, catching sequence), followed by heat inactivation 20 min at 75°C ( C ) or incubation at 4°C ( D ). Eight randomly chosen clones were analyzed by colony PCR using vector primers. The products amplified by colony PCR were separated on a 1% agarose gel supplemented with ethidium bromide and visualized under UV light. The expected insert size is indicated by an arrow.