PCR Assay Diagnostic Aid

Download CL-Res-18-Real-Time-PCR-Ct-Values-1

In a real time PCR assay a positive reaction is detected by accumulation of a fluorescent signal. The CT (cycle
threshold) is defined as the number of cycles required for the fluorescent signal to exceed background levels and
cross a pre-set threshold. CT levels are inversely proportional to the amount of target nucleic acid detected in the
sample (i.e., the lower the CT level the greater the amount of target nucleic acid in the sample).
WVDL real time assays undergo 40 cycles of amplification.