Observations on insulin

Publisher Website
Google Scholar
Abstract
Methods for the preparation of crystalline insulin from commercial preparations are discussed. The most successful method depends on the neutralization, with NH3, of an acidulated, saponin-containing solution of the crude material. At pH 4.5-5.0 a precipitate (15-20% of activity and 30% of the weight) forms. No further precipitation occurs up to pH 5.6. At this reaction crystalline insulin separates on standing over night. These crystals are purified with aid of phosphate buffers. The saponin inhibits the precipitation and sharpens the iso-electric point, but must be used in proper concentration. All saponins are not equally active, this activity being parallel to the hemolytic index. Digitonin functions in the same way but not as effectively. Other methods used were much less effective than the saponin method.

This publication has 1 reference indexed in Scilit: