Quantitation of hyaluronic acid in equine synovia

An assay for the determination of hyaluronic acid concentration in equine synovia (synovial fluid) was investigated. The method involved the degradation of hyaluronic acid, using a highly specific microbial enzyme. The unsaturated tetra- and hexasaccharide products were oxidized with periodate and caused to react with thiobarbituric acid for form a chromophore which absorbed in the visible range of the spectrum. The method was precise within acceptable limits for synovia and compared favorably with the widely used carbazole method of Bitter and Muir (Anal Biochem 4:330-334, 1962). The between-assay coefficient of variation was 1.7% and the method was found to be linear to 100 microgram of hyaluronic acid. The mean value for hyaluronic acid concentration in synovia of health horses was 127 mg/100 ml.