title: A rapid turbidimetric immunoassay for serum antistreptolysin-O.
abstract: We designed a rapid, quantitative turbidimetric immunoassay for serum antistreptolysin-O (ASO), based on the immunoprecipitating velocity with purified streptolysin-O (SLO), which can be measured turbidimetrically at 340 nm. The assay system involves polyoxyethylene mono-p-nonylphenyl ether to accelerate and enhance the immunoprecipitation reaction. No antibody excess phenomenon is observed, up to 1,700 U/ml. Grossly icteric sera can be assayed. Patient sera gave acceptable results. Free cholesterol offers no interference. The standard curve is linear for values up to 800 U/ml. Results measured by the proposed method and those by the conventional microtitration method correlated well. Analytical recovery averaged 90.1% (80.3%-102.5%). Within-run and day-to-day CVs ranged from 2.1% to 3.5% and from 2.5% to 6.9%, respectively. Working SLO is stable for at least 15 days at 4 degrees C. The proposed method has proven to be superior to other available methods for measuring serum ASO.
authors.affiliation: Department of Laboratory Medicine, Faculty of Medicine, Kagoshima University, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Otsuji
authors.forename: T
authors.initials: T
authors.lastname: Kamada
authors.forename: T
authors.initials: T
authors.lastname: Matsuura
authors.forename: M
authors.initials: M
authors.lastname: Seki
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: H
authors.initials: H
authors.lastname: Shibata
authors.forename: T
authors.initials: T
authors.lastname: Honda
mesh_terms: D000989:Antistreptolysin / Q000097:blood* / Q000592:standards; D011232:Chemical Precipitation; D005069:Evaluation Studies as Topic; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D007202:Indicators and Reagents; D009391:Nephelometry and Turbidimetry / Q000379:methods; D017137:Nonoxynol; D011092:Polyethylene Glycols; D012015:Reference Standards
chemical_list: D007202:Indicators and Reagents; D017137:Nonoxynol; D011092:Polyethylene Glycols; D000989:Antistreptolysin