Patent ID: 7090984

Claim:
A method of detecting the presence of an analyte in a biological sample, comprising: (a) providing a development carrier comprising: (i) a test region to which a reactive substance 1 reactive with the analyte is bound; and (ii) a reference region to which a metal compound is bound, wherein the reference region contains a metal compound other than a compound selected from the group consisting of an alkali metal salt, anhydrous copper sulfate and anhydrous cobalt chloride; (b) adding a labeled second reactive substance 2 reactive with the analyte to the biological sample; (c) applying the biological sample from (b) to the development carrier; (d) developing the biological sample through the test region and subsequently through the reference region, such that the labeled reactive substance 1 that has reacted with the analyte becomes bound to the test region and the labeled first substance that has not reacted with the analyte becomes non-specifically blocked by the metal compound; and (e) detecting the presence of the analyte by identifying the presence of the label at both the test region and the reference region.