DNA methylation site analysis method and DNA biosensor

Abstract

The invention belongs to the field of biological genes technology, and discloses a DNA methylation site analysis method and a DNA biosensor. An AuNPs (at) rGO composite material is used for modifying a gold electrode; designing target sequences of a capture probe, an auxiliary probe and different methylation sites; performing DNA hybridization to induce signal amplification of gold nanoparticles aggregation; identifying a methylation site through anti-5methylcytosine antibody specifically; optimizing optimal experiment conditions of an electrochemical sensing analysis technology; performing electrochemical detection; and detecting the methylated DNA in the serum. According to the invention, a triple helix nucleic acid structure is combined with an electrochemical technology, a simple, stable and high-specificity DNA methylation site analysis technology is constructed, the maximum detection number of DNA methylation sites is 7, which is superior to results reported in other literatures, and a new technical means is provided for early clinical diagnosis of gene epigenetic disorder diseases and tumors and selection of a demethylation targeted therapy scheme.

Description

technical field [0001] The invention belongs to the technical field of biological genes, and in particular relates to a DNA methylation site analysis method and a DNA biosensor. Background technique [0002] At present, DNA methylation is the most basic and important modification of epigenetics. A large number of studies have shown that abnormal DNA methylation levels are closely related to the occurrence and development of various tumors, such as: lung cancer CDKN2A, liver cancer ARID2, Colorectal cancer SETP9 has become a marker for early diagnosis of cancer. The DNA sequence can be modified by methylation under the action of methylase, and can also be demethylated under the action of demethylase, and demethylation can restore the expression of methylated genes, Therefore, methylated genes can be used as targets for tumor therapy. At present, although there are demethylation treatment programs and drugs for high DNA methylation levels in clinical practice, most of these ...

AI Technical Summary

Problems solved by technology

[0007] (1) At present, most of the therapeutic drugs for high DNA methylation level in clinical practice are to demethylate DNA non-specifically, and its effect on gene expression is difficult to predict

[0008] (2) Among the currently established methylation analysis technologies at home and abroad, the chemical conversion of bisulfite sequencing is incomplete, and the library construction process is cumbersome and complicated; MSP can only qualitatively analyze one or two CpG sites at a time, and cannot accurately Quantitative

[0009] (3) Due to the specificity of restriction endonucleases for base sequence recognition, MSRE can only analyze specific recognition sequences, and the detection range is limited; enzyme treatment and bisulfite treatment in the methylation chip may bring coming deviation

[0010] (4) At present, the application of electrochemical sensing technology based on triple helix nucleic acid structure in DNA methylation detection has not been reported at home and abroad

[0011] (5) Electrochemical sensing technology for quantitative analysis of DNA methylation based on double helix base pairing, the base pairing pattern of the double helix restricts the base composition of the target sequence, resulting in sequence selection of the constructed DNA biosensor Poor performance and detection efficiency

[0012] The difficulty of solving the above problems and defects is: it is difficult to quantitatively analyze polymethylation sites with simple operation, high stability, high sensitivity and low interference.

Images