The invention relates to the technical field of
colorectal cancer auxiliary detection, and particularly discloses a blood
methylation site combination and a detection kit for early diagnosis of
colorectal cancer, and the method comprises the following steps: providing a blood sample of a person to be detected for obtaining cfDNA; the cfDNA is subjected to
bisulfite treatment, and the transformed
DNA is obtained; amplifying the transformed
DNA by using a
multiplex fluorescence PCR (
Polymerase Chain Reaction) method to obtain
fluorescence signal data of each
gene; calculating a Ct value of each
gene based on the
fluorescence signal data, comparing the Ct value with a preset
Cut-off value, and judging whether the
colorectal cancer exists or not; according to the present invention, the invasive operation of the colonoscope can be replaced, the screening can be completed through the blood sample, the
patient compliance can be significantly improved, the method is suitable for the large-scale early screening, the trace tumor
signal in the blood can be efficiently captured based on the
methylation marker highly related to the colorectal
cancer, and the accurate early canceration identification can be achieved.