Methods are provided for the stabilization of proteinases by the covalent attachment of or admixture with water-soluble polymers. The resultant stabilized proteinases have increased stability under the harsh conditions used in industrial genomics, which permits their use in the extraction and isolation of nucleic acids and the identification of disease-related prion proteins at elevated temperatures in solutions containing chaotropic agents, such as sodium dodecyl sulfate, urea or guanidinium salts, conferring advantages for robotic applications.