Method for preparing nucleic acid or DNA samples and a DNA extraction process using thermophilic proteases

摘要

A method for the preparation for nucleic acid samples in a closed system comprises the steps of: i) adding at least thermophilic proteinase to a sample containing nucleic acid for testing and ii) incubating the sample for a preferred period at 65080oC as required to effect one or more of lysis of cells, digestion of proteins, digestion of cell-wall enzymes, via activity of the thermophilic proteinase, the method further comprises the step of incubating the sample at or above 90oC to effect autolysis and/or denaturation of the thermophilic proteinase wherein the incubation takes place in a closed system without the addition of further denaturing agents. Preferably the thermophilic proteinase is derived from Bacillus sp. str. Ak1 or EA1. Also described are methods of identifying thermophilic proteinases.