Assays

Abstract

An analytical test device useful for example in pregnancy testing, comprises a hollow casing ( 500 ) constructed of moisture-impervious solid material, such as plastics materials, containing a dry porous carrier ( 510 ) which communicates indirectly with the exterior of the casing via a bibulous sample receiving member ( 506 ) which protrudes from the casing such that a liquid test sample can be applied to the receiving member and permeate therefrom to the porous carrier, the carrier containing in a first zone a labelled specific binding reagent is freely mobile within the porous carrier when in the moist state, and in a second zone spatially distinct from the first zone unlabelled specific binding reagent for the same analyte which unlabelled reagent is permanently immobilised on the carrier material and is therefore not mobile in the moist state, the two zones being arranged such that liquid sample applied to the porous carrier can permeate via the first zone into the second zone, and the device incorporating means, such as an aperture ( 508 ) in the casing, enabling the extent (if any) to which the labelled reagent becomes bound in the second zone to be observed. Preferably the device includes a removable cap for the protruding bibulous member.

1 - 38 . (canceled)  
   
   
       39 . An analytical test device comprising 
 (a) a hollow casing;    (b) a porous carrier disposed within the casing and communicating directly or indirectly with the exterior of the casing;    (c) a particulate labeled first reagent that is free to migrate through the porous carrier when the carrier is moistened with a sample;    (d) a second reagent that is immobilized in a detection zone on the porous material such that it is not free to migrate when the carrier is moistened;    wherein after application of a liquid sample containing no analyte, the particulate labeled first reagent interacts with the second reagent in the absence of analyte to capture label at the detection zone and wherein the analyte when present reduces the amount of label that is captured by competitively binding to either the particulate labeled first reagent or the second reagent.    
   
   
       40 . The test device of  claim 39 , wherein said porous carrier is in the form of a strip.  
   
   
       41 . The test device of  claim 39 , wherein said porous carrier is comprised of nitrocellulose.  
   
   
       42 . The test device of  claim 39 , further comprising a porous sample receiving member.  
   
   
       43 . The test device of  claim 42 , wherein said porous sample receiving member is a bibulous member.  
   
   
       44 . The test device of  claim 43 , wherein said bibulous member comprises a removable cap.  
   
   
       45 . The test device of  claim 39 , further comprising a control zone downstream from said detection zone.  
   
   
       46 . The test device of  claim 39 , wherein said test device comprises an aperture at said detection zone through which an analytical result may be observed.  
   
   
       47 . The test device of  claim 45 , wherein said test device comprises an aperture at said control zone through which an analytical result may be observed.  
   
   
       48 . The test device of  claim 39 , wherein said particulate labeled first reagent is selected from the group consisting of: a metallic sol, colored polymer, or colored dye particle.  
   
   
       49 . The test device of  claim 48 , wherein said particulate labeled first reagent is a colored polymer.  
   
   
       50 . The test device of  claim 49 , wherein said colored polymer is latex.  
   
   
       51 . The test device of  claim 48 , wherein said particulate labeled first reagent is a metallic sol.  
   
   
       52 . The test device of  claim 51 , wherein said metallic sol is a gold sol.  
   
   
       53 . The test device of  claim 39 , wherein said analyte is a hapten.  
   
   
       54 . The test device of  claim 53 , wherein said hapten is a drug.  
   
   
       55 . The test device of  claim 39 , wherein said test device comprises a plurality of detection zones for the detection of more than one analyte.  
   
   
       56 . The test device of  claim 55 , wherein said plurality of detection zones are arranged in series through which the aqueous liquid sample can pass progressively.  
   
   
       57 . The test device of  claim 39 , wherein said test device comprises at least two discrete bodies of porous solid phase material each comprising mobile and immobilized reagents.  
   
   
       58 . The test device of  claim 55 , wherein said discrete bodies are arranged in parallel.