Proteinase K is useful for the proteolytic inactivation of nucleases during the isolation of DNA and RNA. It is also useful in removal of endotoxins bound to cationic proteins such as lysozyme and ribonuclease A. It is reported to be useful for the isolation of hepatic, yeast, and mung bean mitochondria. It is useful in determination of enzyme localization on membranes. It is also used in treatment of paraffin embedded tissue sections to expose antigen binding sites for antibody labeling. Proteinase K is used in digestion of proteins from brain tissue samples for prions in Transmissible Spongiform Encephalopathies (TSE) research.