Proteinase K is routinely used in numerous molecular biology applications such as the isolation of genomic, plasmid, and high molecular weight DNA, RNA, and in inactivation of RNases and DNases because of its broad specificity and high stability at a wide range of pH and temperature. It is also used for effective digestion of structural proteins, chromatins, and inactivation of nucleases and RNases.

High-quality sample preparation is an essential step before the actual molecular analysis of the genetic material. This procedure includes multiple stages such as sample isolation, purification, and concentration of the target product, where Proteinase K plays an important role. Despite various reagents used in the process, the initial focus should be on Proteinase K, which certified quality assures high purity of tested nucleic acids.