Method for detecting overall DNA methylation of genome by electrochemical magnetic biosensor

Abstract

The invention discloses a method for detecting overall DNA methylation of a genome by an electrochemical magnetic biosensor. The method is based on a double amplification strategy of a magnetic bead enrichment sample and an enzyme catalysis reaction, and comprises the following steps: firstly, fixing a biotinylated 5-methylcytosine antibody on a magnetic bead of which the surface is covalently coupled with neutral streptavidin; enriching a 5-methylcytosine DNA chain contained in the DNA sample to be detected by the magnetic beads coated with the 5-methylcytosine antibody; carrying out immunoaffinity reaction on the DNA antibody covalently coupled with the glucose oxidase and the magnetic beads with 5-methylcytosine DNA chains captured on the surfaces; in a solution system containing glucose, using the Prussian-blue-doped silk-screen printing carbon electrode on the surface of the magnetic substrate for detecting hydrogen peroxide generated in a glucose reaction catalyzed by glucose oxidase; an electrochemical signal which can be detected on the surface of the working electrode being linearly related to the DNA content of the 5-methylcytosine in a sample to be detected. The device has the advantages of simple instrument, convenience in operation, easiness in microminiaturization and the like.

Description

technical field [0001] The invention belongs to the field of electrochemical sensors, and in particular relates to a method for detecting the overall DNA methylation of a genome by an electrochemical magnetic biosensor. Background technique [0002] DNA methylation is one of the core components of epigenetics, which plays a regulatory role in important life processes such as normal cell function maintenance and embryonic development. DNA methylation refers to the addition of a methyl group to the 5th carbon atom of a cytosine base at a CpG dinucleotide (5’-CpG-3’), resulting in 5-methylcytosine (5-mC). Without changing the base sequence of the gene, the methylation degree of the CpG island is changed to realize the regulation of gene expression at the transcriptional level. Existing studies have found that the reduction of the overall DNA methylation level of the genome and the abnormal changes of CpG island hypermethylation are closely related to the occurrence of many chr...

AI Technical Summary

Problems solved by technology

Methods involving bisulfite pretreatment require extensive clone sequencing steps, which can lead to false positives if incomplete, and cannot distinguish between 5-methylcytosine and 5-hydroxymethylcytosine (5-hmC) ; Methyltransferase analysis then has the problems of unstable enzyme activity and radioactive contamination; although the reagent price of chloroacetaldehyde is low and good in stability, it also avoids radioactive contamination, but time-consuming and laborious, in addition, chloroacetaldehyde is a kind of Toxic Chemicals

Images