[Cryoglobulin analysis by ultracentrifugation in density stabilized gradient followed by immunodiffusion (author's transl)].

A technique is described which combines ultracentrifugation in a density gradient stabilized by gelification, with agar gel immunodiffusion. The use of this procedure to determine sedimentation parameters and antigenic determinations is presented and illustrated with the diagramms obtained in the identification of various cryoglobulins.