The products are the core raw material for nucleic acid extraction after strict screening and quality control. Buffer solution is a kind of solution that can resist the influence of a small amount of strong acids and bases and maintain the pH value of the system basically unchanged. It is very important to maintain pH 4.0-p11.0 in the process of nucleic acid extraction. Nucleic acid is easy to hydrolyze in acidic solution and stable in neutral or weak alkaline solution. Tris, namely trimethylolaminomethane, pH buffer range: 7.0-9.0, can maintain the stability of the nucleic acid released after the cleavage of the sample to be extracted, so as to avoid the degradation of nucleic acid and improve the concentration and purity of nucleic acid. Since Tris reagent cannot be treated with DEPC, it must be strictly determined that there is no RNase in the preparation process of Tris containing reagent. Generally, it must be prepared with DEPC treated water. Therefore, Tris must be of high purity and free of DNase / RNase. This product is a high-purity product, more than 99.99%, and has been strictly tested by RNase / DNase quality control. There is no DNase activity and RNase activity.