Proteinase K

Proteinase K is a broad-spectrum protease for nucleic acid purification. It has been used for isolation of mRNA, high molecular weight DNA and inactivation of other enzymatic activities.

This non-specific serine protease has very high specific activity. The enzyme demonstrates high stability and activity in the presence of SDS, EDTA and chaotropic salts. Proteinase K is free of RNase and DNase activities and has a specific activity of 30 U/mg. The recommended working concentration for Proteinase K is 50–100 µg/mL in the majority of applications in nucleic acid extraction.

Proteinase K is supplied as a lyophilized powder. It is stable at room temperature (15 – 25°C) for up to 4 days. For long term storage, it should be stored at –20°C in a storage buffer. The powder is highly soluble (>50 mg/ml). The standard stock concentration is 20 mg/ml.

Proteinase K is also available as a liquid solution.