Fig. 3.

Direct LAMP detection of HPV in samples without DNA purification: a LAMP detection of HPV in boiled cells. Purified plasmid DNA containing genomic inserts from HPV 16 and HPV 18, as well as boiled Jurkat cells, HeLa cells, UM-SCC47 cells, and Hep3B cells, were amplified using HPV 16 and HPV 18 type-specific LAMP primers. HPV 16 and HPV 18 were detectable in the UM-SCC47 and HeLa cells respectively in type specific fashion, but not in the HPV negative Jurkat and Hep3B cells. The detection of the LAMP products was done by 2% agarose gel electrophoresis, assessment of precipitate formation in the reaction tube, and by presence (+) or absence (−) of spectrophotometer absorbance at 400 nm compared to negative controls. Lane M: 100 bp marker, lane N: negative control, lane 3B: Hep3B cells, lane He: HeLa cells, lane Jur: Jurkat cells, and number: HPV types. b LAMP detection of HPV in boiled UM-SCC47 cell samples in the presence and absence of excess Jurkat cells (DNA equivalents indicated), and in isolated HPV16 OPSCC patient tumor DNA with Jurkat cells. In the presence of Jurkat cells HPV DNA from boiled UM-SCC47 cells and from isolated HPV16 OPSCC patient tumor DNA could be easily amplified in a type specific fashion. These results indicate that LAMP reactions perform robustly in samples without the need for any DNA purification, similar to what would be the case for a tumor swab or biopsy. The detection of the LAMP products was done by 2% agarose gel electrophoresis, assessment of precipitate formation in the reaction tube, and by presence (+) or absence (−) of spectrophotometer absorbance at 400 nm compared to negative controls. Lane M: 100 bp marker, lane N: negative control, and number: HPV types