EpiTect MethyLight Assays enable the direct quantification of the degree of methylation in a sample by using the threshold cycle values (C_T) determined by qPCR. [A] In the FAM channel, the probe detects methylated DNA, and in the [B] VIC channel, the probe detects unmethylated DNA. A 10 µg sample of bisulfite converted, methylated and unmethylated human control DNA, or defined mixtures of both DNAs containing 95% to 5% methylated DNA, as indicated in the figure, were used in a methylation quantification experiment on the ABI PRISM 7900 cycler. The EpiTect MethyLight Assay for HS_CDKN2A was used in combination with the EpiTect MethyLight PCR Kit. The degree of methylation was calculated from the C_T values from the FAM (C_{T (CG)}) and VIC (C_{T (TG)}) channels.

[A] and [C] In methylation-specific TaqMan® assays, two methylation-sensitive TaqMan® probes are present together with methylation-insensitive PCR primers. Depending on the methylation status of the targeted sequence, only the TaqMan® probe specific for bisulfite converted methylated DNA or the TaqMan® probe specific for unmethylated DNA can hybridize to the target sequence. [B] and [D] Both probes are labeled with different fluorophores that are released during PCR if the probe hybridizes to the DNA. The fluorescence from the released fluorophore is proportional to the amount of accumulated PCR product.