Patent ID: 7041459

Claim:
A method for determining the presence or absence of one or more target polypeptides in a sample suspected of containing the target polypeptides, the method comprising the steps of: a)—mixing the sample with a class-specific reagent and one or more electrophoretic probes, wherein the class-specific reagent comprises (i) a cleavage-inducing moiety having an effective proximity and (ii) an immobilized metal affinity chromatography (IMAC) resin that binds a phosphate group on the one or more target polypeptides, and wherein the one or more electrophoretic probes each comprises a binding moiety that specifically binds one of the target polypeptide(s) and one or more electrophoretic tags each attached thereto by a cleavable linkage, under conditions that permit the class-specific reagent and the one or more electrophoretic probes to bind to the one or more target polypeptides; b)—cleaving the cleavable linkage(s) of any of the one or more electrophoretic probes that are within the effective proximity of the cleavage-inducing moiety so that one or more electrophoretic tags are released; and c)—determining the presence or absence of the one or more target polypeptides based on the presence or absence of the released electrophoretic tag(s).