Immuno-agglutination particle suspensions
First Claim
1. A diagnostic particle comprisinga carboxylate-derivatized polymeric core between about 0.2 and about 1.0 micron in diameter,a plurality of avidin moieties linked through amide bonds to said core,a plurality of biotin moieties complexed to said avidin moieties, anda plurality of antibody molecules linked through amide bonds to a significant portion of said biotin moieties, the amount of antibody molecules on the surface of said particle being controlled so that said diagnostic particle may be stably suspended in aqueous medium in the presence of like particles without agglutination, but subsequently agglutinate in the presence of a substance with which said antibody molecules react.
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Accused Products
Abstract
A suspension of diagnostic particles comprising antibody molecules attached to a carboxylate derivatized polymer core is provided for agglutination tests. The antibody is linked to the core through an avidin-biotin bridge. Avidin is joined by an amide bond to carboxyl groups on the core, and biotin is linked by an amide bond to amino groups on the antibody molecule. The core-bound antibody is exposed to a mixture of free biotin and biotinylated antibody to attach a controlled amount of antibody that is consistent with suspension stability prior to its use in a test and rapid cross-linking of suspended particles in the presence of antigen.
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Citations
28 Claims
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1. A diagnostic particle comprising
a carboxylate-derivatized polymeric core between about 0.2 and about 1.0 micron in diameter, a plurality of avidin moieties linked through amide bonds to said core, a plurality of biotin moieties complexed to said avidin moieties, and a plurality of antibody molecules linked through amide bonds to a significant portion of said biotin moieties, the amount of antibody molecules on the surface of said particle being controlled so that said diagnostic particle may be stably suspended in aqueous medium in the presence of like particles without agglutination, but subsequently agglutinate in the presence of a substance with which said antibody molecules react.
- 2. A diagnostic composition comprising a plurality of particles, each particle comprising a carboxylate-derivatized polymeric core between about 0.2 and about 1.0 micron in diameter, a plurality of avidin moieties linked through amide bonds to said core, a plurality of biotin moieties complexed to said avidin moieties and a plurality of antibody molecules linked through amide bonds to a significant portion of said biotin moieties and an aqueous medium in which said particles are suspended, the amount of antibody molecules on each of said particles being controlled so that said particles remain in suspension in said aqueous medium without agglutination, but when a substance reactive with said antibody molecules is introduced into said aqueous medium, said particles agglutinate.
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10. A method of preparing diagnostic particles comprising
providing carboxylate-derivatized polymeric core particles between about 0.2 and about 1.0 micron in diameter, linking avidin molecules to said core particles through amide bonds, binding biotin molecules to antibody molecules through amide bonds, and complexing said core particle-linked avidin with a controlled amount of said antibody molecule-bound biotin, whereby said diagnotic particles may be suspended in aqueous medium without agglutination of said particles, but when a substance reactive with said antibody molecules is introduced into said aqueous medium, said particles agglutinate.
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27. A diagnostic particle comprising
a core between about 0.2 and about 1.0 micron in diameter formed of polymer selected from the group consisting of polyacrylamide and polystyrene, said polymer being carboxylated to between about 0.1 to about 0.5 milliequivalents per gram, between about 1010 and about 1013 avidin molecules bound through amide bonds to said core per cm2 of surface area, neutralizing moieties attached to core surface carboxyl groups that are not linked by amide bonds to avidin, additional non-immunogenic proteinaceous material adsorbed on surfaces of said cores, biotin moieties complexed to said avidin moieties, and about 2× - 1011 and about 2×
1012 antibody molecules linked through amide bonds to biotin moieties per cm2 of surface area of said core. - View Dependent Claims (28)
- 1011 and about 2×
Specification