title: Evaluation of an immunoassay for determination of haptoglobin concentration in various biological specimens from swine.
abstract: OBJECTIVE
  To develop and evaluate an immunoassay based on time-resolved immunofluorometry (TR-IFM) for measurement of haptoglobin concentrations in samples of various body fluids of swine.
  
  
  METHODS
  20 pigs without clinical signs of disease and seronegative for antibodies against major viruses that affect pigs and 30 pigs with clinical signs of disease.
  
  
  METHODS
  Haptoglobin concentrations were measured in samples of serum, saliva, and meat juice obtained from both groups of pigs to evaluate the ability of TR-IFM to differentiate between healthy and diseased pigs. Performance of TR-IFM was evaluated by means of its calibration curve and detection limit, analytic precision during routine operation, and linearity of results for serial dilutions for the 3 types of samples. In addition, performance of TR-IFM was compared with that of a commercial spectrophotometric assay.
  
  
  RESULTS
  The TR-IFM assay involved only 1 step, and the results were obtained in 20 minutes, with good analytic sensitivity and reproducibility. The analytic limit of detection was 0.52 ng/mL. Intra-assay and interassay coefficients of variation ranged from 1.13% to 4.81% and 5.97% to 13.57%, respectively. The method yielded linear results for all sample types. Serum haptoglobin concentrations determined by use of TR-IFM and spectrophotometric assays were highly correlated (r = 0.96). Differences between healthy and diseased pigs with respect to median haptoglobin concentrations were significant for all types of samples.
  
  
  CONCLUSIONS
  The 1-step TR-IFM assay accurately quantified haptoglobin concentrations in serum, saliva, and meat juice samples from swine and may be useful in laboratory and meat inspection settings.
authors.affiliation: Department of Animal Medicine and Surgery, Veterinary College, University of Murcia, 30100 Espinardo, Murcia, Spain.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Gutiérrez
authors.forename: Silvia
authors.initials: S
authors.lastname: Martínez-Subiela
authors.forename: Jose J
authors.initials: JJ
authors.lastname: Cerón
mesh_terms: D000818:Animals; D015200:Fluoroimmunoassay / Q000379:methods / Q000662:veterinary*; D006242:Haptoglobins / Q000378:metabolism*; D008297:Male; D012680:Sensitivity and Specificity; D013552:Swine; D013553:Swine Diseases / Q000378:metabolism*
chemical_list: D006242:Haptoglobins