Limit of Detection (LoD) Determination
The four OaPV genes were detected using ddPCR standard curves of the
positive controls used in the serial dilutions. A calibration curve of
the positive sample dilutions (log10) was plotted against the number of
PCR cycles. The linear range was determined by diluting the positive
controls from 105 to 10−1 copies/μL,
detecting each dilution thrice, taking the average value, and
correlating the result with the theoretical value. The lower detection
limit obtained by ddPCR, with values <1 copies/μL, indicated
high sensitivity.