title: Affinity assisted selection of antibodies for Point of Care TSH immunoassay with limited wash.
abstract: BACKGROUND
  Molecular binding characteristics of several thyroid stimulating hormone (TSH) antibodies were determined for the TSH antigen, along with its closely related endogenous interfering hormones, follicle stimulating hormone (FSH), luteinizing hormone (LH) and chorionic gonadotropin (CG).
  
  
  METHODS
  This data was compared to the same antibodies used in the low wash sandwich ELISA immunoassay system, the Point of Care i-STAT® immunoassay. From this information we developed binding criteria useful in the low wash i-STAT® immunoassay to permit good signal generation from TSH and low cross-reactivity from its interfering hormones. For the TSH Assay we have developed characteristics that enable antibody selection in the i-STAT® immunoassay cartridge. Our antibody screening approach used a dot blot approach as a first screen to select for the most useful antibodies. We then compared a FRET (Förster Resonance Energy Transfer) and electrochemical cartridge approach to determine the appropriate antibody combinations.
  
  
  RESULTS
  Both methods generated similar data, but the FRET method was not capable of differentiating the antibody with the best characteristics as a capture antibody or a detection conjugate in a sandwich ELISA assay. Finally, we performed binding characterizations of the antibodies using each of the above mentioned glycoproteins.
  
  
  CONCLUSIONS
  We found that we need sub-picomolar detection of TSH, and at least 100 fold or higher values for the cross-reacting species.
authors.affiliation: Assay Research, Abbott Point of Care, 185 Corkstown Rd., Ottawa, Ontario, K2H 8V4, Canada.
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.affiliation: 09MC, Building AP20, Diagnostic Research, Abbott Diagnostics Division, Abbott Park, IL 60064, United States.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Skinner
authors.affiliation: 09MC, Building AP20, Diagnostic Research, Abbott Diagnostics Division, Abbott Park, IL 60064, United States.
authors.forename: Qiaoqiao
authors.initials: Q
authors.lastname: Ruan
authors.affiliation: 09MC, Building AP20, Diagnostic Research, Abbott Diagnostics Division, Abbott Park, IL 60064, United States.
authors.forename: Sergey Y
authors.initials: SY
authors.lastname: Tetin
authors.affiliation: Assay Research, Abbott Point of Care, 185 Corkstown Rd., Ottawa, Ontario, K2H 8V4, Canada. Electronic address: bruce.collier@apoc.abbott.com.
authors.forename: G Bruce
authors.initials: GB
authors.lastname: Collier
mesh_terms: D000906:Antibodies / Q000276:immunology*; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D019095:Point-of-Care Systems; D013972:Thyrotropin / Q000276:immunology*
chemical_list: D000906:Antibodies; D013972:Thyrotropin
keywords: Diagnostics; Molecular binding; Point of Care; Thyroid stimulating hormone