Highly Sensitive Sandwich Enzyme Immunoassay for Human Thyroid-Stimulating Hormone (hTSH) in Serum Using Monoclonal Anti-hTSH β-Subunit IgG1-Coated Polystyrene Balls and Polyclonal Anti-Human Chorinic Gonadotropin Fab′-Horseradish Peroxidase Conjugate

Abstract

A highly sensitive sandwich enzyme immunoassay for human thyroid-stimulating hormone (hTSH) in serum is described. Monoclonal anti-hTSH β-subunit IgG₁-coated polystyrene balls were incubated with serum samples and subsequently with polyclonal anti-human chorionic gonadotropin Fab¹-horseradish peroxidase conjugate. Neither hTSH nor anti-hTSH serum was required except for a small amount of hTSH as a standard. The detection limit of hTSH was 0.1 nU/tube or 0.005 mU/1 for most serum samples except for those from pregnant women, since there was no cross-reaction with 209 IU/1 of human follicle-stimulating hormone and 439 IU/1 of human luteinizing hormone when 20 μ1 of serum sample was used. Serum hTSH levels in normal subjects and Graves¹ disease were 1.22 ± 0.70 (SD) mU/1 (range: 0.26–2.65 mU/1) and 0.080 ± 0.062 (SD) mU/1 (range: < 0.005–0.17 mU/1), respectively.