Hybrid phase lateral flow assay

Abstract

The invention relates to devices for performing single step assays for the determination of the presence or absence of an analyte in a liquid sample, and methods of determining the presence or absence of such analytes using such devices. Devices disclosed comprise a labeled analyte-binding reagent reversibly-immobilized on a non-porous solid material, which solid material is in physical contact with a dry porous carrier bearing an immobilized analyte-binding reagent. Also provided are quantitative assay devices.

1 . An analytical device for the single-step determination of the presence of an analyte in a liquid sample comprising a test strip comprising:
 a) a first piece of non-porous solid surface comprising, in a reversible immobilization zone, a reversibly immobilized labeled reagent that binds said analyte to form a complex;   b) a porous carrier comprising, in a detection zone, an immobilized reagent that binds said complex, wherein said porous carrier is in contact with said non-porous solid surface; and   c) a second piece of non-porous solid surface placed over (a) and (b).   
     
     
         2 . The device of  claim 1  wherein, rather than being reversibly immobilized upon the first piece of non-porous solid material, said labeled reagent is reversibly immobilized in a reversible immobilization zone on the surface of said second piece of non-porous solid material that faces said first piece of non-porous material, so that the first piece of non-porous solid material is on the bottom and the labeled reagent is reversibly immobilized on the underside of said second piece. 
     
     
         3 . A method of detecting an analyte, the method comprising
 a) contacting a liquid sample to be tested for said analyte with the analytical device of  claim 1 ; and   b) permitting said liquid sample to traverse said test strip such that said reversibly immobilized labeled reagent is mobilized by the sample and flows to said detection zone, wherein, if analyte is present in said liquid sample, a detectable signal is generated indicative of the presence of said analyte.   
     
     
         4 . A device for the single step quantitative measurement of an analyte in a liquid sample, the device comprising:
 a) a piece of non-porous solid surface comprising, in an immobilization zone, a reversibly immobilized labeled reagent that binds said analyte to form a complex; and   b) a porous carrier comprising a binding reagent and being in contact with said non-porous solid surface, wherein said binding reagent is applied to and immobilized in a detection zone having a longitudinal axis parallel to a flow of a liquid sample, wherein when said liquid sample comprises the analyte, the binding results in a signal, and wherein the distance from the point at which said liquid sample entered said detection zone to the furthest point in said detection zone at which said signal is detected above background is indicative of the amount of analyte present in said sample.   
     
     
         5 . The device of  claim 4  wherein said detection area is at least 1.5 times as long as it is wide. 
     
     
         6 . The device of  claim 4  wherein said detection area extends over at least 50% of the length of said porous carrier. 
     
     
         7 . The device of  claim 4  wherein said detection area extends over the full length of said porous carrier. 
     
     
         8 . A method of detecting an analyte, the method comprising
 a) contacting a liquid sample to be tested for said analyte with the analytical device of  claim 4 ; and   b) permitting said liquid sample to traverse said test strip such that said reversibly immobilized labeled reagent is mobilized by the sample and flows to said detection zone, wherein, if analyte is present in said liquid sample, a detectable signal is generated indicative of the presence or quantity of said analyte.   
     
     
         9 . An analytical device for the single-step determination of the presence or absence of an analyte in a liquid sample comprising a test strip comprising:
 a non-porous solid surface comprising, in a reversible immobilization zone, a reversibly immobilized labeled reagent, that competes with said analyte for binding sites present in the detection zone, and   a porous carrier comprising, in a detection zone, an immobilized reagent that binds said labeled reagent and analyte in a liquid sample, wherein the absence of analyte generates a detectable signal, wherein said porous carrier is in contact with said non-porous surface.   
     
     
         10 . A method of detecting an analyte, the method comprising
 a) contacting a liquid sample to be tested for said analyte with the analytical device of  claim 9 ; and   b) permitting said liquid sample to traverse said test strip such that said reversibly immobilized labeled reagent is mobilized by the sample and flows to said detection zone, wherein, analyte present in said liquid sample will compete for binding sites in the detection zone with said labeled reagent, and a detectable signal is generated indicative of the absence of said analyte.