We compared our reformatted line blot system to the established
dot blot assay to evaluate its performance. In general,
the results from this comparison are highly concordant, both
for overall HPV DNA detection and for genotype-specific discrimination.
Most of the signals from the few discrepant samples
were weak, suggesting low concentration of viral DNA,
with disagreement likely attributable to sampling error and
variable amplification of low levels of HPV DNA. This explanation
is substantiated by the following observations. First, the
design of the study required each laboratory to prepare, amplify,
and detect each sample separately. This procedure creates
at least three separate circumstances wherein subaliquots
of each sample were transferred to a subsequent step in the
protocol. The likelihood of each transfer containing equivalent
concentrations of HPV DNA is low. Second, the discrepant