title: Improved dextran sulfate-calcium chloride method for the removal of nonspecific inhibitors with modifications for nonspecific agglutinin removal in the rubella hemagglutination inhibition test.
abstract: The dextran sulfate precipitation method for removal of nonspecific inhibitors from sera to be tested in the rubella hemagglutination-inhibition test was modified by shortening the dextran sulfate-serum mixture incubation period from 2 hr to 30 min. A comparative study using both treatment times showed no significant difference in rubella antibody titers. Reducing the treatment time even further also gave comparable results, indicating the select 30-min incubation period is not marginal for undertreatment. It was shown that 41.5% of the 159 serums tested had nonspecific agglutinins at levels from 1:8 to as high as 1:64. In each specimen, all demonstrable nonspecific agglutinin was removed by adsorption with 10%, 0- to 2-day-old chick red blood cells rather than the usually recommended 50% adult chicken erythrocytes.
mesh_terms: D000373:Agglutinins; D000818:Animals; D000906:Antibodies / Q000032:analysis; D002122:Calcium Chloride; D011232:Chemical Precipitation; D002645:Chickens / Q000276:immunology; D003911:Dextrans; D004912:Erythrocytes / Q000276:immunology; D005069:Evaluation Studies as Topic; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D012409:Rubella / Q000276:immunology*; D013431:Sulfates; D013997:Time Factors
chemical_list: D000373:Agglutinins; D000906:Antibodies; D003911:Dextrans; D013431:Sulfates; D002122:Calcium Chloride