To obtain nucleic acid, the basic steps include: cell lysis—nucleic acid extraction—nucleic acid washing—elution. After the cell lysis step, the genomic DNA extraction can be performed either with alcohol precipitation or matrix adsorption method. The adsorption matrix materials are mainly: silicon matrix adsorption materials, anion exchange resins and magnetic beads. The silicon matrix adsorption material can specifically adsorb nucleic acid, and it is convenient and quick to use, without the need for using toxic solvents such as phenol, chloroform, etc., making the extraction of genomic DNA as simple as filtering. Therefore, the silicon matrix material is a general method for separating and purifying DNA on a large scale, and for removing impurities such as proteins, polysaccharides, salts and organic solvents. The principle of silicon matrix adsorption is as follows: the application mainly uses its characteristic that DNA and silicon matrix materials combine in high salt condition and separate in low salt condition. The mechanism is that high concentration salt particles destroy the molecular distribution on the surface of silicon matrix, forming electrostatic force generated by cation bridge, and DNA and silicon substrates are bound by hydrophobic interactions. When salt is removed, the rehydrated silicon matrix destroys the interaction between DNA and matrix, resulting in the elution of DNA from the silicon substrate.

The TIANGEN column-based genomic DNA manual extraction kits adopt a novel ultra-micro silicon matrix membrane to protect genomic DNA and ensure DNA integrity.