title: Evaluation of an assay for serum 1,5-anhydroglucitol (GlycoMark) and determination of reference intervals on the Hitachi 917 analyzer.
abstract: BACKGROUND
  1,5-Anhydroglucitol (1,5-AG) is a glucose analogue, which is decreased in hyperglycemic individuals. We report the technical performance of an assay (GlycoMark) on a chemistry analyzer, evaluation of analyte stability and determination of reference intervals for 1,5-AG in a non-diabetic US population.
  
  
  METHODS
  NCCLS protocols were followed to evaluate the reagent on a Hitachi 917 chemistry analyzer.
  
  
  RESULTS
  Intra- and interassay imprecision ranged from 1.3% to 3.8% and 0.79% to 3.7%, respectively. The assay was linear to 110 microg/ml. Interference from triglyceride, hemoglobin and bilirubin was <10% to concentrations of 12.6 mmol/l, 12.1 and 911.4 micromol/l, respectively. Correlation coefficients between lot numbers on the Hitachi 917 and between analyses on the Hitachi 917 and the Hitachi 7170 analyzers were >0.99. The lowest limit of detection was 0.49 microg/ml (mean+/-2 S.D.). 1,5-AG was stable at 4 degrees C for 7 days, at 22 degrees C for 5 days, at -80 degrees C for 14 days and for three freeze-thaw cycles at -80 degrees C. The US reference intervals (nonparametric 2.5th-97.5th percentiles) were 10.2-33.8 microg/ml (males) and 5.9-31.8 microg/ml (females).
  
  
  CONCLUSIONS
  The performance of the GlycoMark assay for the measurement of 1,5-AG was acceptable on the Hitachi 917 analyzer.
authors.affiliation: Linco Diagnostics, St. Charles, MO, USA.
authors.forename: William
authors.initials: W
authors.lastname: Nowatzke
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Sarno
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Birch
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Stickle
authors.forename: Tanya
authors.initials: T
authors.lastname: Eden
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Cole
mesh_terms: D000293:Adolescent; D001322:Autoanalysis / Q000295:instrumentation*; D001663:Bilirubin / Q000097:blood; D015415:Biomarkers; D001786:Blood Glucose / Q000378:metabolism; D003847:Deoxyglucose / Q000097:blood*; D003920:Diabetes Mellitus / Q000097:blood*; D005006:Ethnicity; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D006943:Hyperglycemia / Q000097:blood*; D007118:Immunoassay; D008297:Male; D013696:Temperature; D014280:Triglycerides / Q000097:blood
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006454:Hemoglobins; D014280:Triglycerides; C006584:1,5-anhydroglucitol; D003847:Deoxyglucose; D001663:Bilirubin