To delineate the conditions for the polymerase chain reaction (PCR) using primers specific for human papillomavirus (HPV) types 6b, 16 and 18, a number of important technical features were analysed. Buffer, concentrations of magnesium, Taq polymerase, primers and DNA templates, annealing temperature, and extension time were studied by a combination of gel electrophoresis, Southern and slot-blot hybridization. Amplification of E6 gene fragments of HPV-16 and HPV-18 generated bands of 110 bp and 154 bp respectively, as predicted. However, amplification of a segment within the long control region of HPV 6b yielded an unexpected size of 340 bp. Different conditions were found for each HPV type-specific primer pair. These results, and the applications of PCR in HPV research and in an increasingly wide range of fields in medical virology are discussed. © 1990.