Patent ID: 7635597

Claim:
A dry reagent lateral flow strip assay device for detecting at least one analyte in a test sample within a pre-determined range of analyte concentration using a porous member capable of being traversed by the sample comprising: a) a sample application zone on the porous member having diffusively immobilized therewith a labeled indicator reagent, which does not bind to the analyte; b) at least one test zone having non-diffusively bound thereto a pre-determined amount of a first reagent, based on the pre-determined range of analyte concentration, that that binds to both the labeled indicator reagent and to the analyte to produce a corresponding detectable response in the test zone, the pre-determined amount of the first reagent such that the detectable response is inversely proportional to the analyte concentration; c) at least one reference zone having non-diffusively bound thereto a pre-determined amount of a second reagent, based on the pre-determined range of analyte concentration, that binds to the labeled indicator reagent to produce corresponding detectable response in the reference zone, the pre-determined amount of the second reagent such that the detectable response is directly proportional to the analyte concentration; wherein the sample application zone, the test zone and the reference zone are in fluid communication with one another through the porous member; and wherein the detectable response in the test zone plus the detectable response in the reference zone equal a total detectable response that is substantially constant for the pre-determined range of analyte concentration.