Method for detecting DNA by stacking hybridization fluorescent amplify magnetic separation

Abstract

The invention discloses a laminated crossed fluorescent amplified magnetic separating and detecting method of DNA, which comprises the following steps: marking DNA of two different sequences a and b on the SiO2 nanometer particle simultaneously; marking DNA on the magnetic nanometer particle surface of sequence e; crossing one end of target DNA and the DNA of the sequence b on the SiO2 nanometer particle; crossing the other end of target DNA and DNA of sequence e on the magnetic nanometer particle; marking the DNA of two different sequences c and d on the SiO2 nanometer particle simultaneously; crossing DNA of SiO2 nanometer particle on the sequence c and fluorescent DNA; finishing the first sandwich crossing; crossing the DNA of first sandwich crossed SiO2 nanometer particle on the sequence a and one end of connected DNA; crossing the other end of DNA and the DNA on the nanometer particle on the sequence d after fluorescent cross; cleaning the product after the second sandwich cross through magnetic separation; removing residual fluorescent molecule and non-specific adsorption; denaturizing the DNA after the second sandwich cross; proceeding fluorescent detection for the unlinked fluorescent DNA.

Description

【Technical field】 [0001] The invention relates to a method for detecting DNA. 【Background technique】 [0002] Since Watson and Crick created the double helix structure of biological genetic molecule deoxyribonucleic acid (DNA) and established the molecular mechanism of biological genetic genes in 1953, the identification and sequencing of DNA molecules have been widely recognized by people. focus on. In 1990, the United States formulated the world's largest genetic research program "Human Genome Project". With the publication of the draft human gene, people are conducting in-depth research on the post-genome project. For this reason, research on biochips and biosensors has been launched internationally. upsurge. Genes control the birth, aging, sickness and death process of human life. With the understanding of genes and cancer and other gene-related diseases, the detection of susceptible species and gene mutations at the molecular level is of great significance for the tre...

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Problems solved by technology

[0009] The above-mentioned development of nanoscience and technology has undoubtedly promoted the development of ultra-sensitive recognition technology for biological macromolecules, but overall it is still in the early stages of development, and many problems have not yet been resolved. For example, the high-noise background of immobilized molecular beacons involves the interface Many issues in surface chemistry: stability of nanoparticles, intermolecular interactions, influence of interfaces on molecular motion, steric effects and assembly density of immobilized label molecules and the influence of linker molecule / group length on biomacromolecule recognition etc., it is urgent for people to conduct in-depth discussions

However, due to the need for an amplification process, the optimization of conditions is cumbersome, and it is very sensitive to the influence of reagent quality and environment, and sometimes false positive or false negative results may occur. Therefore, the overall development trend is to use PCR technology and actively explore PCR-free methods. Highly sensitive analytical methods where amplification by nanoparticles is preferred by researchers

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