US 4,208,479 AGranted

Label modified immunoassays

AssigneeSyva Company

InventorsRobert F. Zuk, Edward T. Maggio

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Abstract

Methods and reagents are provided for immunoassays employing as reagents a labelled receptor, where the label is capable of providing a detectable signal, and modifying reagents, capable of modifying the signal obtained from the label. When ligand (ligand analog for monoepitopic ligands) is present in the assay medium, a complex is formed which inhibits interaction between the label modifying reagent and the label. By measuring the signal obtained in the presence of a known amount of ligand in the assay medium and comparing that signal with the signal obtained with an unknown sample suspected of containing ligand, one can qualitatively or quantitatively determine the amount of ligand in the unknown. For determinating anti(ligand) the assay is carried out in substantially the same way, except a source of ligand or ligand analog must be provided.

Claims37

Dependent claims

An assay method for determining a member of an immunological pair comprising a mono- or polyepitopic ligand and an anti(ligand) suspected of being present in a sample;

said method employing:
(1) labeled anti(ligand), wherein the label is capable of providing a detectable signal and said labeled anti(ligand) binds to said polyepitopic ligand to form a complex;
(2) a macromolecular modifier which interacts with said label to modify the signal produced from said label and is inhibited from interacting with said label by said complex;
(3) poly(ligand analog), wherein poly(ligand analog) has a plurality of epitopic sites capable of competing with said monoepitopic ligand for the binding sites of labeled anti(ligand), and capable of binding with anti(ligand) and labeled anti(ligand) to form a complex;
and
(4) polyepitopic ligand;
with the proviso that poly(ligand analog) is only employed in an assay for monoepitopic ligand or anti(ligand) that binds monoepitopic ligand and polyepitopic ligand is only employed in an assay for anti(ligand) that binds polyepitopic ligand;
said method comprising;
(A) combining in an assay medium for a time sufficient to form said complexes which sterically inhibit the approach of the macromolecular modifier to said label:
(i) sample;
(ii) labeled anti(ligand);
(iii) modifier;
(iv) poly(ligand analog) in an assay for monoepitopic ligand or anti(ligand) that binds monoepitopic ligand;
and
(v) polyepitopic ligand in an assay for anti(ligand) that binds polyepitopic ligand;
(B) exposing said assay medium to an agent which interacts with said label to provide said detectable signal;
and
(C) measuring said detectable signal, wherein the measured detectable signal is directly related to the amount of said member in said medium.

15 more elements

An assay method for determining a member of an immunological pair comprising a mono- or polyepitopic ligand and an anti(ligand) suspected of being present in a sample;

said method employing:
(1) labeled anti(ligand), wherein the label is capable of providing a detectable signal and said labeled anti(ligand) binds to said polyepitopic ligand to form a complex;
(2) a Fab anti(label) which interacts with said label to modify the signal produced from said label and is inhibited from interacting with said label by said complex;
(3) poly(ligand analog), wherein poly(ligand analog) has a plurality of epitopic sites capable of competing with said monoepitopic ligand for the binding sites of labeled anti(ligand), and capable of binding with anti(ligand) and labeled anti(ligand) to form a complex;
and
(4) polyepitopic ligand;
with the proviso that poly(ligand analog) is only employed in an assay for monoepitopic ligand or anti(ligand) that binds monoepitopic ligand and ligand is only employed in an assay for anti(ligand) that binds polyepitopic ligand;
said method comprising:
(A) combining in an assay medium for a time sufficient to form complexes which sterically inhibit the approach of the Fab anti(label) to said label:
(i) sample;
(ii) labeled anti(ligand);
(iii) Fab anti(label);
(iv) poly(ligand analog) in an assay for monoepitopic ligand or anti(ligand) that binds monoepitopic ligand;
and
(v) ligand in an assay for anti(ligand) that binds poly(epitopic ligand);
(B) exposing said assay medium to an agent which interacts with said label to provide said detectable signal;
and
(C) measuring said detectable signal, wherein the measured detectable liquid is directly related to the amount of said member in said medium.

15 more elements

Dependencies are inferred from the claim text.