Patent ID: 8586316

Claim:
A method comprising: (a) contacting a sample with a plurality of binding moieties that specifically bind a target molecule of the sample, wherein at least two binding moieties are bound to the same target molecule; (b) contacting the binding moieties bound to the target molecule with a plurality of detection moieties, which specifically bind to the binding moieties forming a detection complex, wherein the binding moieties are antibodies, which bind to multiple epitopes on the same target molecule, and the detection moieties are fluorophore-labeled antibodies; (c) introducing the sample containing the detection complex into a polyethylenimine (PEI)-coated channel of at least 100 nm in width; and (d) detecting the detection complex by 2D photon counting, using photon counts as a function of time from a single detection channel to determine single molecule or single complex detection.