Enzyme-Linked Competitive Binding Assays Based on the Biotin/Avidin Interaction.

Homogeneous Enzyme-linked Competitive Binding Assay for Biotin Based on the Avidin-biotin Interaction

A homogeneous enzyme-linked competitive-binding assay for biotin with glucose-6-phosphate dehydrogenase (GGPDH), is described. This assay is based on the interaction between a GGPDH/biotin conjugate with avidin, a natural binder for biotin. In the absence of biotin in the assay mixture, this interaction results in 100% inhibition of the enzyme conjugate. In the presence of biotin, the enzymatic...

Enzyme-Linked Immunosorbent Assay Competitive Binding Inhibition

Solid phase enzyme-linked competitive binding assay for riboflavin.

A new solid-phase enzyme-linked assay for riboflavin (vitamin B2) is described. The assay is based on the competition between analyte vitamin molecules and a glucose-6-phosphate dehydrogenase-3-carboxymethylriboflavin conjugate for a limited number of riboflavin-binding protein sites immobilized on Sepharose particles. Significant improvements in conjugate catalytic activity and thus detectabil...

H9mogeneous Enzyme-linked Competitive Binding Assay for Riboflavin

A rapid and precise homogeneous enzyme-linked competitive binding assay for riboflavin (vitamin Bz) is described. The method utilizes a malate dehydrogenase/3-carboxymethylriboflavin conjugate in conjunction with soluble riboflavin binding protein. In the absence of the vitamin, the catalytic activity of the enzyme/riboflavin conjugate is inhibited up to 71% by the binding protein. In the prese...

Malaria diagnosis by enzyme-linked immunosorbent assays.

Enzyme-linked immunosorbent assays (ELISA) for detecting malarial parasites in blood were tested on uninfected monkeys and in monkeys infected with Plasmodium falciparum. A double antibody sandwich ELISA detected one malarial cell per 10(3) uninfected cells, and an inhibition ELISA detected on infected cell per 10(4) uninfected erythrocytes. These methods are not yet as sensitive as conventiona...