Electrophoresis studies of human synovial mucin.

A characteristic property of synovial fluids is the formation of a mucin clot when a weak acid is added. The physical character of the clot may be of some aid in the diagnosis of rheumatoid arthritis (Ropes, Bennett, Cobb, Jacox & Jesser, 1957; Ropes & Bauer, 1953). The clot has also been used as a preliminary step in the isolation of hyaluronic acid (Meyer, Smyth & Dawson, 1939) and its hexosamine content as a measure of the hyaluronic acid (Ogston & Stanier, 1950; Hamerman & Schuster, 1958). Previous electrophoretic studies of synovial mucin have indicated that the clot is composed of hyaluronic acid and protein (horse mucin; Blix, 1940); hyaluronic acid, albumin and y-globulin (horse and human mucin; Hesselvik, 1940); and hyaluronic acid or complex, albumin and other proteins (Ogston & Stanier, 1952; Ropes, Robertson, Rossmeisl, Peabody & Bauer, 1947). Chemical studies had shown hyaluronic acid and 'globulin' as components (Meyer et at. 1939), whereas ultracentrifuge analyses showed the presence of a hyaluronic acid complex and albumin (cattle mucins; Ogston & Stanier, 1950, 1952). The work described in this paper is a part of a basic study of the composition and significance of human synovial mucin. The composition as indicated by electrophoretic analysis is the principal subject of this paper.