Visualization of reversible macromolecular reactions in an analytical ultracentrifuge

It has been shown that the saw-like disturbances of sedimentation observed in an analytical ultracentrifuge are not caused by convective disturbances of the solution but result from a special type of intermolecular reaction of reversible association/dissociation. A qualitative theory of saw-like anomalies has been suggested and the sedimentation and kinetic conditions of their origin have been indicated. Such reactions are a frequent occurrence in the serum of patients affected with rheumatic diseases and acute myocardial infarction. Experimental data indicate the involvement of immunoglobulins (viz., low-affinity antibodies) which form reversible immune complexes. Saw-like sedimentation patterns, especially those of the schlieren type, are a direct testimony to reversible association/dissociation reactions in macromolecular solutions, whereas other experimental methods provide only oblique evidence.