To obtain nucleic acid, the basic steps include: cell lysis—nucleic acid extraction—nucleic acid washing—elution. After the cell lysis step, the RNA extraction can be performed either with organic solvent extraction or matrix adsorption method. The principle of using RNA silica-membrane technology to achieve RNA separation and purification is mainly to utilize the binding of nucleic acid to silica matrix material under high salt conditions and detachment under low salt conditions. The mechanism is that high concentration of salt ions destroy the molecular structure of silica matrix and water, forming a cationic, so that the nucleic acid is easily bound to the silica matrix; when the salt is washed away, the silica can be rehydrated, and the rehydrated silica destroys the attraction between the matrix and the nucleic acid. RNA can then be eluted from the silica membrane by RNase-Free deionized water.

The TIANGEN column-based RNA extraction kits can effectively remove the Impurities such as proteins and organic solvents with optimized buffer, such as Buffer RW1, and high-purity RNA can thus be obtained very conveniently.