Isolation of mouse transferrin using salting-out chromatography on Sepharose CL-6B

A new method for the isolation of considerable quantities of mouse transferrin is described. This technique employs salting-out chromatography on Sepharose CL-6B, a new step in the preparation of plasma proteins. This step is followed by ion-exchange chromatography on DEAE-Sepharose CL-6B and gel filtration on Sephacryl S-200. The isolated mouse transferrin was shown to be pure by immunoelectrophoresis, sodium dodecyl sulphate-polyacrylamide gel electrophoresis and by the 465 nm/410 nm ratio of absorbances being 1.41. The molecular weight was determined to be about 77 500. The advantages of this procedure are that it is reproducible, gives a high recovery, and can be extended to a larger scale. The advantage over other protein purification techniques is its general utility, due to the fact that there is no need for species-specific antibodies. The application of this method offers a rapid purification of sufficient quantities of mouse transferrin essential for the elucidation of biological functions of this protein and investigations of its molecular structure.