US 6,818,455 B2Granted

Capillary immunoassay and device therefor comprising mobilizable particulate labelled reagents

AssigneeInverness Medical Switzerland GmbH

InventorsKeith May, Michael Evans Prior, Ian Richards

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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.

Claims14

Dependent claims

An analytical test device for detecting an analyte suspected of being present in a liquid biological sample and requiring solely the application thereto of said liquid biological sample to enable a test to be performed and a test result to be provided, said device comprising:

a hollow casing constructed of moisture impervious solid material;
a test strip comprising a dry porous earner disposed in said casing, said dry porous carrier comprising a test result zone and a control zone;
and
a labeled reagent capable of specifically binding with said analyte to form a first complex of said labeled reagent and said analyte, said labeled reagent comprising a particulate direct label and being positioned within said casing as part of said test strip prior to use,
said casing including sample application aperture through which liquid biological sample can be supplied directly or indirectly to said carrier, said labeled reagent being located upstream from said test result zone prior to use and being released into mobile form by contact with said liquid biological sample,
said carrier including, immobilized in said test result zone, a second reagent for specifically binding said first complex, wherein migration of said liquid biological sample through said dry porous carrier by capillarity conveying said first complex to said test result zone where said second reagent binds to said first complex thereby to form a second complex and to thereby indicate the presence of said analyte in said liquid biological sample,
said casing further comprising a test result observation aperture spaced apart from said sample application aperture, said test result zone being visible through said test result observation aperture, wherein the test result observation aperture is substantially shielded to prevent accidental application of sample liquid directly to a portion of said test strip downstream from the location of said labeled reagent through the test result observation aperture, and
said control zone includes a material for indicating that said liquid biological sample has been conveyed thereto by capillarity along said carder irrespective of the presence or absence of said analyte in said liquid biological sample.

5 more elements

A pregnancy testing device for detecting human chorionic gonadotrophin (hCG) suspected of being present in a urine sample and requiring solely the application thereto of said urine sample to enable a test to be performed and a test result to be provided, said device comprising:

a hollow casing constructed of moisture impervious solid material;
a test strip, comprising a dry porous carrier disposed in said casing, said dry porous carrier having a detection zone and a control zone;
and
labeled reagent comprising an anti-hCG antibody bearing a particulate direct label, said anti-hCG antibody being capable of specifically binding with said hCG to form a first complex of said labeled anti-hCG antibody and said hCG,
said casing comprising a sample application aperture through which urine can be applied directly or indirectly to said carrier, said labeled anti-hCG antibody being located upstream from said detection zone prior to use and being released into mobile form by contact with said urine sample,
said carrier comprising, immobilized in said detection zone, a reagent for selectively binding said first complex, and wherein migration of said applied urine sample through said dry porous carrier conveys by capillarity said first complex of labeled anti-hCG antibody and said hCG to said detection zone of said dry porous carrier, where said reagent binds said first complex to form a second complex and thereby indicate the presence of said hCG in said urine sample,
said casing further comprising a test result observation aperture spaced apart from said sample application aperture, said detection zone being visible through said test result observation aperture, wherein the test result observation aperture is substantially shielded from to prevent accidental application of urine directly to a portion of said test strip downstream from the location of said labeled anti-hCG antibody through the test result observation aperture, and
said control zone comprises a reagent for indicating that said urine sample has been conveyed thereto by capillarity along said carrier irrespective of the presence or absence of hCG in said urine sample.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/794,061Filed 28 Feb 2001 · continuation
Priority: GB 870987327 Apr 1987
Published: US 2001/0041368 A115 Nov 2001
Granted: 16 Nov 2004
Term ends: Not estimatedThe source records don’t support an estimate.

Classification23 codes

G01N 33/54366
With an insoluble carrier for immobilising immunochemicals: apparatus specially adapted for solid-phase testing
G01N 33/54388
Immunochromatographic test strips: based on lateral flow
G01N 33/548
The carrier being organic: carbohydrates, e.g. dextran
G01N 33/549
The carrier being organic: with antigen or antibody entrapped within the carrier

Family

PCT/GB88/00322Parent of this continuation · filed 26 Apr 1988
Application07/795,266Parent of this division · filed 19 Nov 1991
Application07/876,449Parent of this continuation · filed 30 Apr 1992
Application08/102,313Parent of this division · filed 15 Jul 1993
Application08/474,192Parent of this continuation · filed 7 Jun 1995
US 2001/0041368 A1Pre-grant publication · published 15 Nov 2001
US 6,228,660 B1Parent of this continuation
Application08/474,192Parent of this division
US 5,622,871 AParent of this division
Application08/102,313Parent of this continuation
Application07/876,449Parent of this division
Application07/795,266Parent of this continuation
Application07/294,146Parent of this continuation
US 6,818,455 B2This patent

From the US filing history. Foreign family members aren’t listed.