A Modified Method for the Preparation of Renin

Abstract

Partially purified renin has been prepared in several laboratories from NaCl or cold acetone extracts of the kidney cortex.1-4 Recently modifications in our original extraction procedure2 have been introduced which eliminate many of the more cumbersome manipulations involved, with considerable saving of time, without sacrificing the relative high potency of the final product.Extraction Procedure. Demedullated kidneys are ground, frozen, and, before thawing, reground into 2% NaCl solution (10 liters to 3 kg tissue). It is possible to use fresh, unfrozen kidneys, but the extraction appears to be less complete. After the salt extract has been stored for 24 hours under toluene, the meat sludge is removed by straining and centrifuging (Sharpies). The pH is then lowered to 4.5. After an interval of 12 to 24 hours to insure complete precipitation, the heavy precipitate is removed by centrifuging (Sharpies) and filtering through Hyflo Super-Cel.† For easier handling in subsequent procedures, the filtrate, adjuste...