Binding assay using binding agents with tail groups

A method of preparing a solid support having a plurality of different antibody species immobilized thereon at discrete locations, wherein each species of antibody has binding sites capable of binding to a given analyte and each species of antibody is attached to an oligonucleotide tail group capable of hybridizing to a capture agent, said method comprising:

• a) immobilizing a plurality of different species of capture agents at discrete locations on the solid support, wherein the different species of capture agents comprise different oligonucleotide having sequences that are capable of hybridizing to the oligonucleotide tail group of a given antibody;
• and
• b) contacting the plurality of different species of antibodies with the solid support having the plurality of capture agents immobilized thereon so that the antibodies become specifically bound to their respective capture agents by the hybridisation of the plurality of different capture agents to the complementary sequences of the tail groups of their corresponding antibody.