title: Evaluation of an enzymatic homocysteine assay for the Hitachi series chemistry analyzer.
abstract: BACKGROUND
  Homocysteine is an essential amino acid, whose clinical utilization includes detection of homocystinuria, vitamin B12 and folate deficiencies and cardiovascular disease management. We report assay performance of the Catch reagents on the Hitachi 917 chemistry analyzer.
  
  
  METHODS
  Linearity, recovery, imprecision and interference from lipids, bilirubin, hemoglobin and ascorbic acid were determined on a Hitachi 917 chemistry analyzer. Split sample aliquots were assayed using the described method, by HPLC and fluorescence polarization immunoassay for method comparisons.
  
  
  RESULTS
  The assay was linear to at least 45 micromol/l. Intra- and interassay variation ranged from 1.7% to 3.4% and 3.3% to 6.7%, respectively. Interference was observed when hemoglobin concentrations was >7 g/l and intralipid >5 g/l. No interference was observed from bilirubin or ascorbic acid. The assay was in good agreement with values obtained by HPLC and fluorescence polarization immunoassay.
  
  
  CONCLUSIONS
  The performance of the Catch homocysteine assay was acceptable on the Hitachi 917 chemistry analyzer.
authors.affiliation: Department of Laboratory Medicine, Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02155, USA. mark.kellogg@childrens.harvard.edu
authors.forename: Mark D
authors.initials: MD
authors.lastname: Kellogg
authors.forename: Reina
authors.initials: R
authors.lastname: Parker
authors.forename: Anthony
authors.initials: A
authors.lastname: Ricupero
authors.forename: Nader
authors.initials: N
authors.lastname: Rifai
mesh_terms: D000328:Adult; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation* / Q000379:methods; D002624:Chemistry, Clinical / Q000295:instrumentation* / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D016231:Fluorescence Polarization Immunoassay / Q000379:methods; D006710:Homocysteine / Q000032:analysis*; D006801:Humans; D016014:Linear Models; D012016:Reference Values; D012044:Regression Analysis
chemical_list: D006710:Homocysteine