The Role of Guanidine Hydrochloride, Guanidine Isothiocyanate And Proteinase K In Nucleic Acid Extraction

Nucleic acid extraction refers to the process of separating nucleic acids from samples by physical and chemical methods. High quality nucleic acids are the key step in molecular biology. Guanidine hydrochloride, guanidine isothiocyanate, and proteinase K all have the effect of denaturing proteins, and are widely used in nucleic acid extraction.

Guanidine hydrochloride, CAS number: 50-01-1, is a white crystalline powder. Guanidine hydrochloride is a strong inhibitor of nucleases, but not a strong denaturant. Its main role in nucleic acid extraction is to denature proteins and inhibit enzyme activity. Guanidine hydrochloride can quickly destroy cell membranes, allowing proteins to denature and precipitate, allowing nucleic acids to get rid of the protein.

Guanidine isothiocyanate, CAS number: 593-84-0, is a white crystalline powder. Guanidine isothiocyanate is a powerful class of protein denaturants, without RNase and DNase activity. In the extraction of nucleic acids, guanidine isothiocyanate can quickly break cells or viruses to release nucleic acids, inhibit the nucleases released by cells, and ensure the integrity of the primary structure of nucleic acids.

Proteinase K, CAS number: 39450-01-6, is a lyophilized powder. Proteinase K is a serine protease with broad cleavage activity, which has the function of strongly degrading and digesting proteins. In nucleic acid extraction, proteinase K can digest proteins that bind to DNA, allowing DNA to be released and dissolved in solution. It is worth mentioning that proteinase K can be stable in a variety of chemical reagents that can denature proteins, such as SDS, urea, EDTA chelating agents and sulfhydryl reagents (such as trypsin inhibitors or chymotrypsin inhibitors), and At the same time maintain the ability to dissolve proteins.

Guanidine hydrochloride and guanidine isothiocyanate are common guanidine salts in nucleic acid extraction lysates, which not only provide a high-salt environment, but also inactivate nucleases, release nucleic acids, and protect nucleic acid molecules. Proteinase K is also commonly used in lysates. According to public reports, in some nucleic acid extraction methods, such as magnetic bead extraction, it can co-exist with guanidine hydrochloride or guanidine isothiocyanate to act as a strengthening solution.

Related links: guanidine hydrochloride, guanidine isothiocyanate, proteinase K