[Rapid Assay of Hyaluronic Acid in Serum]

A method for measurement of hyaluronic acid (HA) level in serum was developed based on using "hyaluronic acid binding protein" (HABP)-coated polystyrene beads. After the beads and test serum being mixed, the mixture was incubated together with reaction buffer for 2 hours, and then the beads were washed. Subsequently, biotinylated HABP was added to the washed beads and incubated for 1 hour. Then peroxidase-conjugated avidin was added to the mixture and incubated again for 1 hour. After the beads being washed, a substrate solution was added to the washed beads and left for 1 hour. Then the reaction was stopped by adding 2N-H2SO4. The absorbance at 492 nm was recorded. The analytical range of HA in serum by this method was found to be between 10-800 micrograms/l, and the precision of the HA assay (CV%) was between 3.0-8.4 in the "with-in" assay (n = 10), and 4.8-8.9 in the "between" assay (n = 5). The analytical recovery of HA assay was between 92-115%. In this study, the results in screening of the serum HA level in RA patients (n = 107), OA patients (n = 16) and healthy subjects (n = 30) showed that the HA level of RA patients was demonstrated significantly higher than that of healthy subjects and OA patients.