title: Luminescent oxygen channeling assay (LOCI): sensitive, broadly applicable homogeneous immunoassay method.
abstract: Luminescent oxygen channeling assay (LOCI) is a homogeneous immunoassay method capable of rapid, quantitative determination of a wide range of analytes--including high and very low concentrations of large and small molecules, free (unbound) drugs, DNA, and specific IgM. Assays have been carried out in serum and in lysed blood. Reliable detection of 1.25 microU/L thyrotropin (TSH) and 5 ng/L hepatitis B surface antigen (HBsAg) corresponds to detection limits approximately 3- and approximately 20-fold lower, respectively, than those of the best commercially available assays. An assay of chorionic gonadotropin is capable of quantification over a 10(6)-fold range of concentrations without a biphasic response. Latex particle pairs are formed in the assay through specific binding interactions by sequentially combining the sample and two reagents. One particle contains a photosensitizer, the other a chemiluminescer. Irradiation causes photosensitized formation of singlet oxygen, which migrates to a bound particle and activates the chemiluminescer, thereby initiating a delayed luminescence emission. Assay times range from 1 to 25 min.
authors.affiliation: Research Department, Behring Diagnostics Inc., San Jose, CA 95161-9013, USA.edwin.ullman@bdi.hcc.com
authors.forename: E F
authors.initials: EF
authors.lastname: Ullman
authors.forename: H
authors.initials: H
authors.lastname: Kirakossian
authors.forename: A C
authors.initials: AC
authors.lastname: Switchenko
authors.forename: J
authors.initials: J
authors.lastname: Ishkanian
authors.forename: M
authors.initials: M
authors.lastname: Ericson
authors.forename: C A
authors.initials: CA
authors.lastname: Wartchow
authors.forename: M
authors.initials: M
authors.lastname: Pirio
authors.forename: J
authors.initials: J
authors.lastname: Pease
authors.forename: B R
authors.initials: BR
authors.lastname: Irvin
authors.forename: S
authors.initials: S
authors.lastname: Singh
authors.forename: R
authors.initials: R
authors.lastname: Singh
authors.forename: R
authors.initials: R
authors.lastname: Patel
authors.forename: A
authors.initials: A
authors.lastname: Dafforn
authors.forename: D
authors.initials: D
authors.lastname: Davalian
authors.forename: C
authors.initials: C
authors.lastname: Skold
authors.forename: N
authors.initials: N
authors.lastname: Kurn
authors.forename: D B
authors.initials: DB
authors.lastname: Wagner
mesh_terms: D000956:Antigens, Viral / Q000032:analysis; D006063:Chorionic Gonadotropin / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D004077:Digoxin / Q000032:analysis; D004958:Estradiol / Q000032:analysis; D035921:Hepatitis A Antigens; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D007118:Immunoassay / Q000379:methods*; D007211:Indoles; D054833:Isoindoles; D008163:Luminescent Measurements; D018625:Microscopy, Atomic Force; D010100:Oxygen; D013806:Theophylline / Q000032:analysis; D013972:Thyrotropin / Q000032:analysis
chemical_list: D000956:Antigens, Viral; D006063:Chorionic Gonadotropin; D035921:Hepatitis A Antigens; D006514:Hepatitis B Surface Antigens; D007211:Indoles; D054833:Isoindoles; D004958:Estradiol; D004077:Digoxin; D013972:Thyrotropin; D013806:Theophylline; D010100:Oxygen; C013647:phthalocyanine