Fig. 4

Amplicons of long range HPV16 PCR from established cell line from a tonsil carcinoma at passage 2 (lane 1) and 8 (lanes 2–5 show 2-fold dilution series of template input to PCR). Lane 1: passage 2, input 15 ng, lane 2: passage 8, 37 ng, lane 3: passage 8, 18 ng, lane 4: passage 8, 9 ng. lane 5: passage 8, 4.5 ng. Lane 6: positive control, 5000 copies of cloned HPV16. Lane 7: negative control, water. Wm: Gene Ruler 100–10,000 bp (Thermo Fisher Scientific). The arrow indicates the position of an amplicon of 7900 bp