Elecsys® HCG STAT (Elecsys® 2010, cobas e 411 analyzer) Electrochemiluminescence immunoassay (ECLIA) for the in vitro quantitative determination of human chorionic gonadotropin (hCG) in serum and plasma (short turnaround time) Indication HCG is produced in the placenta during pregnancy and its role is to maintain the corpus luteum. It also influences steroid production. HCG exists as a number of isohormones and the serum of pregnant women contains mainly intact hCG.1–3 Measurement of hCG levels is used clinically to diagnose pregnancy as early as one week after conception. In addition, elevated hCG concentrations during the first trimester are indicative of chorionic carcinoma, hydatidiform mole, or multiple pregnancy, whereas decreased levels are associated with threatening or missed abortion, ectopic pregnancy, gestosis, or intra-uterine death.1–3 Test principle: sandwich immunoassay Biotinylated monoclonal antibody against hCG (epitope only present in holo-hCG) Streptavidin-coated microparticle Free β−hCG in the sample 4.5 min Measurement Ru Ru 1st Incubation (4.5 minutes): 10 μL of the sample is incubated with both a biotinylated, monoclonal hCGspecific antibody and a ruthenylated, monoclonal hCG-specific antibody to form a sandwich complex. Ru Ruthenylated monoclonal antibody against human β−hCG Ru 4.5 min holo-hCG in the sample 2nd Incubation (4.5 minutes): Streptavidin-coated microparticles are added to the reaction mixture and the complex binds to the solid phase via biotin–streptavidin interactions. Measurement: The reaction mixture is transferred to a measuring cell and the microparticles are magnetically captured onto the surface of an electrode; unbound sample is washed away before a chemiluminescent reaction is induced by applying a voltage to the electrode. Chemiluminescence is measured by a photomultiplier and the concentration of HCG within the sample is calculated using a calibration curve. Elecsys® HCG STAT test characteristics Testing time Test principle Calibration Sample material Sample volume Lower detection limit Measuring range Traceability 9 minutes Sandwich immunoassay 2 point Serum, Li-, Na-, NH4+-heparin, K3-EDTA, sodium citrate, and sodium fluoride/potassium oxalate plasma 10 μL 0.500 mIU/mL 0.500 – 10,000 mIU/mL Standardized against the 4th International Standard for Chorionic Gonadotropin from the National Institute for Biological Standards and Control (NIBSC) 75/589 Intermediate precision (CLSI) Elecsys® 2010 analyzer, cobas e 411 analyzer: 1.9 – 3.1 % (10.6 – 4,634 mIU/mL) Expected values N 97.5th percentile Upper 95 % confidence limit Non-pregnant premenopausal women 182 ≤1 mIU/mL 4.9 mIU/mL Postmenopausal women 143 ≤7 mIU/mL 8.1 mIU/mL 100 tests 4 x 1 mL 2 x 3 mL each 2 x 16 mL 03300811 190 03303071 190 11731416 190 11732277 122 2 x 36 mL 03183971 122 Order information Elecsys® HCG STAT HCG STAT CalSet PreciControl Universal 1 and 2 Diluent Universal or Diluent Universal References 1 Cole, L.A. (1997). Immunoassay of human chorionic gonadotropin, its free subunits, and metabolites. Clin Chem 43, 2233 – 2243. 2 Cole, L.A. (2009). New discoveries on the biology and detection of human chorionic gonadotropin. Reprod Biol Endocrinol 7, 8 – 44. 3 Cole, L.A., (2010). Biological functions of hCG and hCG-related molecules. Reprod Biol Endocrinol 8, 102 – 115. COBAS, COBAS E, ELECSYS and LIFE NEEDS ANSWERS are trademarks of Roche. Not for distribution in the USA. ©2012 Roche Roche Diagnostics International Ltd. CH-6343 Rotkreuz Switzerland www.cobas.com
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