Double receptor fluorescent immunoassay

Abstract

Abstract A novel sensitive method for determining qualitatively and quantitatively the presence of a wide variety of physiologically active organic compounds (ligand) and their receptors is provided. The method employs a reagent which involves bonding a compound having structural similarity to the compound to be determined (ligand analog) to a fluorescing compound. The unknown compound is referred to as a ligand, the conjugate of the structurally similar compound and fluorescer is referred to as ligand analog-fluorescer, and compounds which recognize a specific structure and bind to such structure as referred to as receptors and are normally antibodies. The fluorescer which is chosen will have either a change is quantum yield or a change in its emission and/or absorption spectra or all of them, when bound to antibody, as compared to being unbound. For the purposes of the assay, all that is required is that there be a change in the emission intensity at some wavelength or band of wavelengths. The rate at which fluorescer antibody binds to the fluorescer portion of the ligand analog-fluorescer or the amount of fluorescer antibody bound to the fluorescer portion of the ligand analog-fluorescer at equilibrium will be related to the amount of ligand antibody bound to the ligand analog portion of the ligand analog-fluorescer. Therefore, by combining antibodies to both ligand and fluorescer, with ligand analog-fluorescer and an unknown, one can determine the amount of ligand present in the unknown by relating the emission intensity at a particular wavelength or band of wavelengths to standards. Alternatively, by combining an unknown containing antiligand with fluorescer antibody and ligand analog-fluorescer, one can determine the amount of receptor in the unknown.

Inventors

• 👤 Edwin F. Ullman

Bibliographic Details