Importance

Loading Importance Indicators...

Abstract

The present invention provides methods for determining the concentration of analytes in liquid samples in which the amount of binding agent having binding sites specific for a given analyte in the liquid sample is immobilized in a test zone on a solid support, the binding agent being divided into an array of spatially separated locations in the test zone. The concentration of the analyte is obtained by back-titrating the occupied binding agent with a developing agent having a marker and integrating the signal from each location in the array. The present invention also provides a method for determining a value representative of a fraction of binding sites of the binding agent which are occupied by the analyte, comprising immobilizing the specific binding agent on a solid support, wherein the specific binding agent used for the fractional occupancy is present in an amount less than 0.1 V/K moles, where V is the volume of the liquid sample and K is the association constant for the analyte specifically binding to the binding agent, and wherein the specific binding agent is divided into an array of spatially separated locations; contacting the support with the liquid sample; contacting the support with the developing agent; separating non-specifically bound developing agent and measuring the signal at each of the locations to obtain a value which represents the fraction of the binding sites occupied by the analyte at each location; and adding the measured values to provide a total signal which indicates the fraction of the binding sites of the binding agent occupied by the analyte. Test kits and devices used in practicing these methods are also disclosed.

Loading the Abstract Image...

First Claim