Reagents, kits and methods for immunodetection of epitopes on molecules

A method for detecting molecules expressing a selected epitope in a sample comprising:

• (a) immobilizing a molecule expressing a selected epitope in a sample to a solid support;
• (b) contacting the solid support with a molecule that specifically binds to the selected epitope, streptavidin and a biotinylated oligonucleotide that comprises an RNA polymerase promoter, wherein the molecule that specifically binds to the selected epitope is a monoclonal antibody that comprises a universal epitope, a FAb that comprises a universal epitope, a F(Ab)2 that comprises a universal epitope, humanized or chimeric antibody that comprises a universal epitope, a single chain Fv that comprises a universal epitope, a constrained epitope specific CDR that comprises a universal epitope, a CDR mimetic that comprises a universal epitope, or a engineered CDR structure that comprises a universal epitope, wherein the solid support is additionally contacted with a biotinylated molecule that binds to the universal epitope, wherein the biotinylated molecule that binds to the universal epitope is a biotinylated monoclonal antibody, a biotinylated FAb, a biotinylated F(Ab)2, a biotinylated humanized or chimeric antibody with or without a human Fc a biotinylated single chain Fv, a biotinylated constrained epitope specific CDR, a biotinylated CDR mimetic, or a biotinylated engineered CDR structure,
• whereby the molecule that specifically binds to the selected epitope also binds to the selected epitope of the molecule immobilized to the solid support and to the biotinylated molecule that binds to the universal epitope which binds to the streptavidin which binds to the biotinylated oligonucleotide that comprises an RNA polymerase promoter;
• (c) amplifying the oligonucleotide by RNA amplification to produce an RNA amplification product that is not labeled with a radioactive label or a fluorescent label;
• (d) contacting said amplified oligonucleotide with a fluorescent dye which stains the RNA amplification product;
• and
• (e) detecting fluorescence emitted from the stained RNA amplification product that allows linear quantification of the molecule comprising the selected epitope being present in the sample.