Extraction method for micro amount of DNA in soil-containing sample material

Abstract

The invention discloses an extraction method for a micro amount of DNA in a soil-containing sample material. The method includes the following steps: (1) putting the soil-containing sample material into a centrifuge tube, adding a lysis solution, performing lysis treatment at 90-100 DEG C, and performing centrifugation to obtain a supernatant; (2) adding carboxylic acid group cationic resin, performing uniform mixing, performing heating treatment in a metal bath at 60-90 DEG C, performing centrifugation, and extracting the supernatant; (3) adding an adsorption solution and a magnetic bead suspension, performing uniform mixing, performing magnetic absorption, and discarding all the liquid; (4) adding a washing solution I into the centrifuge tube, performing washing, performing magnetic absorption, discarding the supernatant, repeating the above operation by using a washing solution II, and repeating the above operation by using a washing solution III; and (5) after materials in the centrifuge tube are completely dried, adding high-purity water, performing shaking for uniform mixing, performing warm bath in a metal bath at 65 DEG C for 10 min, performing uniform mixing, and performing magnetic absorption to obtain the DNA solution. The method can effectively extract the micro amount of DNA from the soil-containing sample material, and has the advantages of high sensitivity, strong anti-impurity interference ability, a high detection rate, and broad application prospects.

Description

technical field [0001] The invention belongs to the technical field of biological and medical examinations, and in particular relates to a method for extracting trace DNA in soil-containing specimens. Background technique [0002] DNA testing technology is an important component of current forensic testing technology. By sequencing and analyzing DNA samples collected at the scene of the case, short tandem repeat (STR) typing is the main technical means for forensic individual identification and paternity testing. At present, forensic DNA testing includes the collection of DNA samples, DNA extraction and purification, PCR amplification and typing detection, among which the extraction and purification of trace amounts of DNA is the premise of subsequent testing and plays an important role in obtaining effective STR typing. important role. [0003] Various commonly used DNA purification methods can be divided into two categories: liquid phase purification and solid phase purif...

AI Technical Summary

Problems solved by technology

There are sites on the surface of soil impurities that can interact with phosphate groups in DNA, which are adsorbable to DNA and can compete with DNA solid-phase carriers to adsorb DNA, which makes it more difficult to extract and purify DNA with a low content; at the same time, due to the Due to the complexity of the field environment, some metal ions, humic acid and other inhibitors will inevitably exist in the soil-containing samples collected from the field. If they cannot be effectively purified in the extraction process, it will affect the subsequent PCR amplification. This further increases the difficulty of extracting and purifying trace amounts of DNA from soil-containing samples, which are often a vital source of evidence in case detection

With the development of forensic DNA technology, there are more and more demands for DNA extraction and purification in this type of test material. Failure to effectively extract and purify DNA will directly lead to a low detection rate of DNA in this type of test material, which cannot meet the growing demand. case inspection needs

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