title: Ultrasensitive flow-based immunoassays using single-molecule counting.
abstract: BACKGROUND
  Immunoassay (IA) technology has expanded the clinical utility of protein biomarkers, but demands for increased sensitivity, dynamic reporting ranges, and small sample volumes have limited the potential clinical usefulness of many biomarkers. We assessed the performance, including limits of detection (LODs) and the dynamic reporting range, of an IA-based technology, Erenna Immunoassay System, for a series of biomarkers, including cardiac troponin I (cTnI).
  
  
  METHODS
  Erenna IAs were used with 10 different and clinically important biomarkers to ascertain the LOD with various sample sizes (10 microL to 200 microL).
  
  
  RESULTS
  The Erenna Immunoassay System generated LODs of 10-100 pg/L using 100 microL of sample. For cTnI, the LOD was 0.2 ng/L and a 10% CV was seen between 0.78 and 1.6 ng/L.
  
  
  CONCLUSIONS
  The Erenna IA-based technology reproducibly measures protein biomarkers with detection limits of 10-100 pg/L, with a dynamic range of >4.5 logs in sample volumes of 50-150 microL.
authors: Singulex, Inc., Hayward, CA 94545, USA. j.todd@singulex.com
authors: John
authors: J
authors: Todd
authors: Bob
authors: B
authors: Freese
authors: Ann
authors: A
authors: Lu
authors: Douglas
authors: D
authors: Held
authors: Jennifer
authors: J
authors: Morey
authors: Richard
authors: R
authors: Livingston
authors: Philippe
authors: P
authors: Goix
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000097:blood; D004285:Dogs; D000882:Haplorhini; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D051381:Rats; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019210:Troponin I / Q000097:blood
chemical_list: D015415:Biomarkers; D019210:Troponin I