Abstract: Methods, compositions and articles of manufacture are provided for conducting specific binding assays to determine the concentration or presence of at least one analyte in a sample. At least two dendrimer-reagent preparations with different analyte specificities may be immobilized on a solid phase. Alternatively, at least one dendrimer-reagent preparation having multiple specificities may be immobilized on a solid phase. Immobilization is facilitated by coupling specific binding assay reagents such as polypeptide receptors or analytes with water soluble polymers. Such water soluble polymers, for example star polymers such as dendrimers, provide production advantages of lot-to-lot uniformity and homogeneity, and can enhance sensitivity due to low non-specific binding to the solid phase.

Abstract: Compositions are disclosed, comprising dendrimers to which a first polypeptide is controllably coupled. Such polypeptide-dendrimer compositions are effective for controllably coupling a second polypeptide to the dendrimer. The first and second polypeptides have separate and distinct defined biological activities, for example, two antibodies with first and second binding specificities or an antibody and an enzymatic label. Such compositions are useful as indicators in specific binding assays, e.g., immunoassays. Methods for sequentially coupling two different polypeptides to a dendrimer to form compositions of the invention also are disclosed.

Abstract: Methods are provided for conducting specific binding assays to determine the concentration or presence of at least one analyte in a sample. Dendrimer-reagent preparations with particular analyte specificities are mixed in solution with a sample to form dendrimer-reagent-sample complexes. The complexes are then immobilized on a solid phase. Immobilization is facilitated by coupling specific binding assay reagents such as polypeptide receptors or analytes with water soluble polymers. Such water soluble polymers, for example star polymers such as dendrimers, provide production advantages of lot-to-lot uniformity and homogeneity, and can enhance sensitivity due to low non-specific binding to the solid phase.