Reagent compounds, compositions, kits, and methods for amplified assays

The instant disclosure provides reagent compounds, and antibody and oligonucleotide reagents, for use in a variety of assays, including immunoassays and nucleic acid hybridizations. The reagent compounds comprise a bridging antigen or bridging oligonucleotide and a latent crosslinker moiety, such as a tyramide moiety. The bridging antigens are recognizable by the antibody of a corresponding antibody reagent with high affinity, and the bridging oligonucleotides are complementary to the oligonucleotide of a corresponding oligonucleotide reagent. The antibody reagents and oligonucleotide reagents also comprise a crosslinker activation agent, such as a peroxidase enzyme. Reaction of the reagent compounds with the crosslinker activation agent results in the amplification of signal in assays for target cellular markers, including cellular antigens and nucleic acids. Also provided are detectable antibodies specific for the bridging antigens, kits comprising the reagent compounds and antibody and oligonucleotide reagents, methods of signal amplification using the compounds and reagents of the disclosure, methods of preparation of the compounds and reagents, and compositions comprising the compounds and reagents.