Detection method for colorectal cancer polygene ctDNA

Abstract

The invention discloses a detection method for colorectal cancer polygene ctDNA, which specifically comprises the following steps: S1, collecting a pre-treatment tissue specimen; S2, treating a blood sample; S3, performing cfDNA extraction; S4, measuring the concentration and detecting the size of a fragment; S5, performing mixing and centrifuging; S6, performing a ddPCR detection stage; S7, reading a fluorescence signal; and S8, analyzing a numerical result. The invention relates to the technical field of molecular diagnosis gene detection. According to the detection method for the colorectal cancer polygene ctDNA, ddPCR amplification is performed on cfDNA through a specific detection primer and a probe of a reference gene beta-Actin; an amplification product is detected; finally, fluorescence signal data is analyzed; fluorescence information of KRAS, NRAS, PIK3CA and BRAF genes and the reference gene beta-Actin is obtained; plasma ctDNA possibly replaces tumour tissue biopsy; and as a molecular marker for auxiliary diagnosis of colorectal cancer, change of RAS (KRAS, NRAS), BRAF and PIK3CA gene mutation states in ctDNA of a patient before and during cetuximab treatment is dynamically monitored.

Description

technical field [0001] The invention relates to the technical field of molecular diagnostic gene detection, in particular to a detection method for colorectal cancer multigene ctDNA. Background technique [0002] At present, clinical colorectal cancer genetic testing is basically obtained from tumor tissue, but tissue acquisition is an invasive operation, and it is difficult to repeat it multiple times in the same patient, especially for advanced patients, it is even more difficult to obtain samples. This means that when tissue samples are lost, insufficient, or biopsy is difficult due to disease progression, it is impossible to accurately formulate individualized treatment plans for patients, which also limits the research on the molecular mechanisms of primary and secondary drug resistance. Therefore, it is very important to clinically explore gene detection methods with wide application range, less pain, high accuracy and low cost. [0003] ctDNA gene detection is a "liq...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the deficiencies of the prior art, the present invention provides a method for detecting multigene ctDNA in colorectal cancer, which can replace invasive tumor tissue biopsy, ctDNA is easy to obtain, and is more easily accepted by patients. Cell-free DNA released into peripheral blood in the form of death, necrosis or autocrine, the tumor genome information carried by it has good consistency with tumor tissue, and can overcome the problem of tumor heterogeneity that conventional tumor tissue biopsy cannot break through

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