Particles for immunoassays and methods for treating the same
AssigneeRoche Diagnostics Operations, Inc.
InventorsChristopher C. Lawrence, Wei Yuan, Armen B. Shanafelt
Life of this patent
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Abstract
A method of treating particles to be used in immunoassays reduces interference in particle agglutination assays. For particles having covalently bound antibodies and residual NHS-ester or sNHS-ester groups on the surface, the reactive esters are treated with an aqueous mixture containing an amine compound of formula (I): H2N—R—X (I). The moiety —X is —NH2, —OH, or —CO2CH2CH3; and R is an alkyl group or an alkyl ether group. When —X is —NH2 or —CO2CH2CH3, R contains from 1 to 20 carbon atoms; and when —X is —OH, R contains from 4 to 20 carbon atoms.
Claims14
A method of preparing particles for immunoassays, comprising:
- reacting particles comprising carboxylate groups with N-hydroxysuccinimide or N-hydroxysulfosuccinimide and with a carbodiimide coupling reagent to provide activated particles comprising succinimide ester groups;
- contacting said activated particles with antibodies to provide sensitized particles comprising covalently bound antibodies and residual succinimide esters;
- and
- treating said sensitized particles in an aqueous mixture with an amine compound selected from the group consisting of 2,2′-(ethylenedioxy)bisethylamine and 4,7,10-trioxa-1,3-tridecanediamine
- wherein the treatment results in the reaction of the succinimide ester groups with the amine functionality of the amine compound to form an amide linkage.
A sensitized particle for use in immunoassays, comprising:
- a particle comprising a surface;
- at least one antibody bound to the surface through a covalent bond from reaction of an N-hydroxysuccinimide or N-hydroxysulfosuccinimide/carbodiimide-activated carboxylate group on the particle surface with an amine group on the antibody;
- and
- the reaction product of a succinimide ester on the surface and an amine compound selected from the group consisting of 2,2′-(ethylenedioxy)bisethylamine and 4,7,10-trioxa-1,3-tridecanediamine,
- the reaction product being covalently attached to the particle surface.
A particle for use in immunoassays, comprising:
- a polymer particle comprising a surface;
- at least one antibody bound to the surface through a covalent bond from reaction of an N-hydroxysuccinimide or N-hydroxysulfosuccinimide/carbodiimide-activated carboxylate group on the particle surface with an amine group on the antibody;
- BSA on the surface;
- and
- the reaction product of a succinimide ester and an amine compound on the surface;
- wherein the amine compound is selected from the group consisting of 2,2′-(ethylenedioxy)bisethylamine and 4,7,10-trioxa-1,3-tridecanediamine;
- wherein the reaction product is covalently attached to the particle surface;
- wherein the particles covalently bind less than 0.35 milligrams per square meter of non-specific protein when contacted with serum;
- and
- wherein the particles physically adsorb less than 2 milligrams per square meter of non-specific protein when contacted with serum.
A reagent, comprising:
- a plurality of particles;
- each of said particles comprising a surface;
- an antibody bound to the surface through a covalent bond from reaction of an N-hydroxysuccinimide or N-hydroxysulfosuccinimide/carbodiimide-activated carboxylate group on the particle surface with an amine group on the antibody;
- and
- the reaction product of a succinimide ester on the surface and an amine compound selected from the group consisting of 2,2′-(ethylenedioxy)bisethylamine and 4,7,10-trioxa-1,3-tridecanediamine,
- the reaction product being covalently attached to the particle surface.
Dependencies are inferred from the claim text.