title: Preparation of a portable point-of-care in vitro diagnostic system, for quantification of canine C-reactive protein, based on a magnetic two-site immunoassay.
abstract: In this study, characterization of the binding kinetics and optimization of a magnetic permeability based point-of-care (POC) immunoassay system for quantification of canine C-reactive protein (cCRP) is described. The reagent is based on a two-site heterogeneous immunoassay system utilizing conjugated superparamagnetic nanoparticles (SPION) and silica particles, both particles carrying covalently linked antibodies directed to the cCRP analyte. Detection is carried out using a magnetic permeability-based small instrument, adjusted in order to apply it in a POC setting near the patients. The kinetic parameters are characterized and applied in the final design of the assay system. In the cCRP system studied, 90% of the binding between immobilized solid-phase silica antibody and cCRP is complete after only 15 s, and 30 s for the binding between the antibody on the SPION and the bound cCRP on the silica particle. Additionally, the binding rate constants are determined to be 149 and 30 M(-1)s(-1), respectively. The analytical sensitivity, clinical sensitivity, and imprecision verifies the clinical usefulness of the system. Also, quantification of cCRP, using the system described, in dog clinical samples from mixed breeds shows a high correlation to a commercially available comparative cCRP ELISA system (y = 0.98 × +3.2, R(2) = 0.98, n = 47). The immunoassay system described can thus provide the veterinarian a valuable tool for rapid diagnosis and monitoring of inflammatory diseases in dogs in a setting near the patients.
authors: LifeAssays AB, IDEON Science Park, 223 70, Lund, Sweden. filiz.ibraimi@lifeassays.com
authors: Filiz
authors: F
authors: Ibraimi
authors: Björn
authors: B
authors: Ekberg
authors: Dario
authors: D
authors: Kriz
authors: Gertrud
authors: G
authors: Danielsson
authors: Leif
authors: L
authors: Bülow
mesh_terms: D000818:Animals; D000906:Antibodies / Q000737:chemistry; D002097:C-Reactive Protein / Q000032:analysis*; D002138:Calibration; D004285:Dogs; D004797:Enzyme-Linked Immunosorbent Assay; D004867:Equipment Design; D007118:Immunoassay / Q000379:methods* / Q000662:veterinary*; D007700:Kinetics; D057230:Limit of Detection; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity; D012822:Silicon Dioxide
chemical_list: D000906:Antibodies; D012822:Silicon Dioxide; D002097:C-Reactive Protein