Assay device and method

Abstract From the Canadian patent

An assay method is described, which comprises the steps of immobilizing a binding partner (e.g. an antigen or antibody) for an analyte to be detected (e.g. an antibody or antigen) on a portion of a surface of a microfluidic chamber; passing a fluid sample over the surface and allowing the analyte to bind to the binding partner; allowing a metal colloid e.g. a gold- conjugated antibody, to associate with the bound analyte; flowing a metal solution e.g. a silver solution, over the surface such as to form an opaque metallic layer; and detecting the presence of said metallic layer e.g. by visual inspection or by measuring light transmission through the layer conductivity or resistance of the …