Preparation of enzyme extracts from liver

Claim 1

IN A PROCESS FOR OBTAINING FROM LIVER TISSUE AT LEAST ONE ENZYME SELECTED FROM THE GROUP CONSISTING OF CATALASE, CATHEPSIN AND ARGINASE, SAID TISSUE BEING SELECTED FROM THE GROUP CONSISTING OF BEEF LIVER TISSUE AND HOG LIVER TISSUE, THE STEPS OF WASHING SAID TISSUE WITH A MIXTURE OF WATER AND ETHANOL AT A TEMPERATURE RANGING FROM -3 TO -15* C., SAID ETHANOL BEING PRESENT IN SAID MIXTURE WHILE IT IS IN CONTACT WITH SAID TISSUE IN CONCENTRATIONS RANGING FROM 40 TO 50% BY VOLUME, EXTRACTING THE RESIDUAL SOLID MATERIAL WITH WATER AT A PH RANGING FROM 6.3 TO 6.7, SUBSEQUENTLY SUBJECTING THE EXTRACT THUS OBTAINED TO AN ISOELECTRIC PRECIPITATION AT A PH WITHIN THE RANGE FROM 5.2 TO 5.4 TO OBTAIN A PURIFIED ENZYME EXTRACT, FRACTIONATING SAID EXTRACT AT A PH RANGING FROM 5.4 TO 6.2, AT AN IONIC STRENGTH BELOW .1, AND AT A TEMPERATURE BETWEEN -3 TO -15*C. BY ADDING AN ORGANIC SOLVENT THERETO TO A CONCENTRATION OF BETWEEN 20 TO 50% BY VOLUME SAID ORGANIC SOLVENT BEING SELECTED FROM THE GROUP CONSISTING OF ETHANOL AND METHANOL, AND SEPARATING THE RESULTING PRECIPITATE FROM THE SUPERNATANT.