One-step, labeled-antibody assay for measuring free thyroxin. I. Assay development and validation.

@article{Christofides1992OnestepLA,
  title={One-step, labeled-antibody assay for measuring free thyroxin. I. Assay development and validation.},
  author={Nicholas D Christofides and C P Sheehan and John Midgley},
  journal={Clinical chemistry},
  year={1992},
  volume={38 1},
  pages={11-8}
}
We describe a one-step, labeled-antibody radioassay for measuring free thyroxin (FT4) in serum or plasma, based on a novel principle. FT4 in the sample competes with a gross molar excess (over antibody) of a cross-reactant (L-triiodothyronine, T3), chemically coupled to magnetizable polymer particles, for binding to avid 125l-labeled monoclonal anti-thyroxin antibodies. As in conventional immunoassays, 125I counts bound to the solid phase (T3-magnetizable particles) are inversely proportional… CONTINUE READING