Method for the selection of specific affinity binders by homogeneous noncompetitive assay

A method for screening specific affinity molecules to target molecules using a homogeneous non-competitive assay, said method comprising:

• a) providing reagents of a homogeneous non-competitive assay, comprising:
• i) a target molecule,
• ii) a first affinity molecule, wherein the first affinity molecule is a reference affinity molecule and is known to bind the target with relatively high affinity,
• iii) a reference detection molecule that is a first member of a complementary pair, wherein the reference detection molecule is fused to the first affinity molecule;
• b) combining a second affinity molecule with said reagents of a homogeneous non-competitive assay, wherein said second affinity molecule comprises a candidate affinity molecule fused to a complementary detection molecule that is a second member of the complementary pair, wherein the binding affinity of the candidate affinity molecule for the target is not known, and wherein said reference detection molecule and said complementary detection molecule generate a measurable signal upon binding of said reference and candidate affinity molecules to said target, and
• c) identifying candidate affinity molecules with affinity for said target as those that generated a measurable signal in said homogeneous non-competitive assay.