USING THE POLYMERASE CHAIN-REACTION TO GENOTYPE HUMAN PAPILLOMAVIRUS DNAS IN SAMPLES CONTAINING MULTIPLE HPVS MAY PRODUCE INACCURATE RESULTS

Compared with other laboratory techniques, the polymerase chain reacti on (PCR) is a simple, rapid, sensitive method for detecting human papi llomavirus (HPV) DNA in cervical samples. However, since many cervical samples contain multiple HPV types, we decided to investigate whether PCR results from such samples accurately reflected the relative amoun ts of each HPV type present. Theoretical calculations of product accum ulation when multiple DNAs with different amplification efficiencies a re present in the same sample were done. In addition a set of samples in which cloned HPV DNAs were mixed in varying proportions prior to PC R was tested. Finally, four clinical samples containing multiple HPV t ypes by hybridization assays were subjected to PCR, using two differen t primer sets. Each of these lines of investigation showed that select ive amplification of one HPV DNA over another can occur when mixed HPV types are present. This effect may lead to inaccurate information reg arding both types and relative amounts of HPV DNAs in samples containi ng multiple HPV types. A protocol to avoid this problem is described.