title: Validation of a commercially available immunoassay for the measurement of bovine cardiac troponin I.
abstract: BACKGROUND
  Commercially available cardiac troponin I (cTnI) assays developed for use in humans have not yet been validated for use in cattle.
  
  
  OBJECTIVE
  The ADVIA Centaur TnI-Ultra immunoassay can be used for the detection of bovine cTnI. In healthy cattle, serum cTnI is undetectable or is present only in trace amounts.
  
  
  METHODS
  Purified bovine cTnI and cTnI-free bovine serum were used for the evaluation of assay performance including intra- and inter-assay precision, sensitivity, interference, linearity, and recovery. Effects of storage at 23, 4, -20, and -80 degrees C for 2 days, and at -20 and -80 degrees C for 7 and 14 days and repeated freeze-thaw cycles on recovery of cTnI were analyzed. Serum cTnI concentrations in 30 healthy dairy cows were determined.
  
  
  RESULTS
  Intra- and inter-assay precisions (mean +/- SD) were 4.48 +/- 2.26 and 13.36 +/- 6.59%, respectively. The assay demonstrated linearity at 0.5, 2, 15, and 30 ng/mL cTnI. Mean recovery was 100.81, 85.26, 87.72, and 114.42%, respectively. Skeletal muscle homogenate added to serum of known cTnI concentration did not alter the concentration of the analyte (P > .05). Concentration of cTnI significantly decreased when samples were stored at 4 and 23 degrees C for 2 days (P < .05). Repeated freeze-thaw cycles and storage at -20 degrees C for 7 days had no significant influence on cTnI concentration (P > .05). Serum cTnI concentration in healthy cattle was <or=0.03 ng/mL.
  
  
  CONCLUSIONS
  ADVIA Centaur can be used reliably for the detection of serum cTnI concentration in cattle.
authors.affiliation: Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, USA.
authors.forename: A
authors.initials: A
authors.lastname: Varga
authors.forename: K E
authors.initials: KE
authors.lastname: Schober
authors.forename: W L
authors.initials: WL
authors.lastname: Walker
authors.forename: J
authors.initials: J
authors.lastname: Lakritz
authors.forename: D
authors.initials: D
authors.lastname: Michael Rings
mesh_terms: D000818:Animals; D009202:Cardiomyopathies / Q000097:blood / Q000175:diagnosis / Q000662:veterinary*; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood* / Q000175:diagnosis; D005260:Female; D007118:Immunoassay / Q000379:methods / Q000662:veterinary*; D011247:Pregnancy; D011933:Reagent Kits, Diagnostic / Q000662:veterinary*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood*
chemical_list: D011933:Reagent Kits, Diagnostic; D019210:Troponin I