Density gradient centrifugation.
Card's contents:LABORATORY TECHNIQUES IN BIOCHEMISTRY AMD MOLECULAR BIOLOGY vol.6. 536,346 HINTON RICHARD, DOBROTA MILOSLAV Density gradient centrifugation. Part 1. CHARD T. An introduction to radioimmunossay and related techniques. Part 2. Amsterdam 1978 North-Holland Publ. Co. 8° s. VIII, 534, il. Laboratory Techniques in Biochemistry and Molecular Biology vol. 6.