Purification of human alpha-2-macroglobulin by chromatography on Cibacron Blue Sepharose.

A simple and efficient procedure has been devised for the isolation of α-2-macroglobulin from human plasma (type 1-1 haptoglobulin). The primary step is gel filtration and affinity chromatography on Cibacron Blue Sepharose, which selectively removes albumin and retards lipoproteins and γ-globulin, while effecting the molecular sieving of the remainder of the plasma proteins. This results in the separation of about 40% of the α-2-macroglobulin as a homogeneous component. A second step, gel filtration on Ultrogel AcA 22, may be utilized to separate α-2-macroglobulin in contaminated fractions obtained after Cibacron Blue Sepharose chromatography.