All Photos(1)



Proteinase K, Lyophilized

Highly active serine protease that exhibits broad cleavage specificity on native and denatured proteins and is widely used in the purification of DNA and RNA.

Proteinase K from Tritirachium album, Endopeptidase K
CAS Number:
Enzyme Commission number:
MDL number:



mol wt

28.93 kDa



storage condition

OK to freeze

shipped in

wet ice

storage temp.


Looking for similar products? Visit Product Comparison Guide

General description

Proteinase K is a highly active 28,904-Daserine protease isolated from the fungusTritirachium album. The enzyme exhibitsbroad cleavage specificity on native anddenatured proteins and is widely used in thepurification of DNA and RNA. Its activityis increased in the presence of denaturantssuch as SDS (1%) and elevated temperature(50-60°C). The recommended workingconcentration is 50-100 µg/ml for proteinremoval and enzyme inactivation, and up to2 mg/ml for tissue treatment. The Proteinase K,Lyophilized powder can be prepared as a20 mg/ml stock solution in water and storedin aliquots at -20°C. The enzyme is alsoavailable as a ready-to-use concentrated stocksolution (600 mAU/ml) that is convenientfor routine use in most applications. 1 mgof Proteinase K is the equivalent of 30 mAU(AU = Anson unit). The Novagen ProteinaseK products are free of detectable DNase andRNase


Useful for the proteolytic inactivation of nucleases during the isolation of DNA and RNA.
Removes endotoxins that bind to cationic proteins such as lysozyme and ribonuclease A.
Reported useful for the isolation of hepatic, yeast, and mung bean mitochondria
Determination of enzyme localization on membranes
Treatment of paraffin embedded tissue sections to expose antigen binding sites for antibody labeling.
Digestion of proteins from brain tissue samples for prions in Transmissible Spongiform Encephalopathies (TSE) research.


100 mg in Plastic ampoule
500 mg in Glass bottle

Biochem/physiol Actions

Proteinase K is a stable and highly reactive serine protease. Evidence from crystal and molecular structure studies indicates the enzyme belongs to the subtilisin family with an active-site catalytic triad (Asp39-His69-Ser224). It is stable in a broad range of environments: pH, buffer salts, detergents (SDS), and temperature. In the presence of 0.1-0.5% SDS, proteinase K retains activity and will digest a variety of proteins and nucleases in DNA preparations without compromising the integrity of the isolated DNA.


Toxicity: Harmful (C)

Unit Definition

One AU (AU = Anson unit) is defined as the amount of enzyme that liberates 1.0 µmol (181 µg) of tyrosine from casein per minute at pH 7.5 at 37°C.

Legal Information

NOVAGEN is a registered trademark of Merck KGaA, Darmstadt, Germany


Health hazard

Signal Word


Hazard Statements

Hazard Classifications

Eye Irrit. 2 - Resp. Sens. 1 - Skin Irrit. 2

Storage Class Code

11 - Combustible Solids



Certificate of Analysis

Enter Lot Number to search for Certificate of Analysis (COA).

Certificate of Quality

Enter Lot Number to search for Certificate of Quality (COQ).

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service