Molecular biomarkers for the detection of metastatic colorectal cancer cells

Figure 1 Outline of quantitative methylation-specific polymerase chain reaction analysis in peritoneal lavage. The depth of invasion and subsequent increased likelihood of tumor cells exfoliated from colonic serosa is reflected in the presence of tumor-related methylated DNA in peritoneal cavity. In quantitative methylation-specific polymerase chain reaction (PCR) step, the DNA polymerase cleaves only probes that are hybridized to the target. Cleavage separates the reporter dye (R) from the quencher dye (Q); resulting in increased fluorescence by the reporter. The increase in fluorescence signal occurs only if the target sequence is complementary to the probe and is amplified during PCR.