Lateral flow chromatographic binding assay device

Claim 2

A test device for determining the presence or amount of an analyte substance in a sample by means of one or more specific binding reactions comprising; a chromatographic medium having capillarity and the capacity for chromatographic solvent transport of one or more reactive sample components and non-immobilized reagents including a reaction site at which is present an immobilized reagent capable of binding a member from the group consisting of said analyte substance and a labelled specific binding material, a sample application means located adjacent to said chromatographic medium and offset upstream from said reaction site, and a liquid absorption means offset downstream from said reaction site.

Claim 3

The test device according to claim 1 wherein said liquid absorption means is said chromatographic medium.

Claim 4

The test device according to claim 1 wherein said liquid absorption means offset downstream from said reaction site is located adjacent to said chromatographic medium.

Claim 5

4 . The test device according to claim 1 wherein a member of a signal generating substrate/ cofactor group is immobilized at said reaction site.

Claim 6

The test device according to claim 4 wherein nitroblue tetrazolium is immobilized at said reaction site

Claim 7

6 A method for determining the presence or amount of an analyte substance in a sample which method utilizes; a chromatographic medium having capillarity and the capacity for chromatographic solvent transport of one or more non- immobilized reagents and reactive sample components including a reaction site at which is present an immobilized reagent capable of binding a member from the group consisting of said analyte substance and a labelled specified binding material, a sample application means located adjacent to said chromatographic material and offset upstream from said reaction site, and a liquid absorption means offset downstream from said reaction site, said method comprising; (a) applying a volume of said sample to said sample application means whereby said sample is transported along said chromatographic medium through said reaction site to said sample adsorption means, (b) contacting said labelled specific binding material to said reaction site, and (c) determining the presence or amount of labelled specific binding material immobilized at said reaction site as an indication of the presence or amount of the substance in the sample

Claim 8

6 A method for determining the presence or amount of an analyte substance in a sample which method utilizes; a chromatographic medium having capillarity and the capacity for chromatographic solvent transport of one or more non- immobilized reagents and reactive sample components including a reaction site at which is present an immobilized reagent capable of binding a member from the group consisting of said analyte substance and a labelled specified binding material, a sample application means located adjacent to said chromatographic material and offset upstream from said reaction site, and a liquid absorption means offset downstream from said reaction site, said method comprising; (a) applying a volume of said sample to said sample application means whereby said sample is transported along said chromatographic medium through said reaction site to said sample adsorption means, (b) contacting said labelled specific binding material to said reaction site, and (c) determining the presence or amount of labelled specific binding material immobilized at said reaction site as an indication of the presence or amount of the substance in the sample

Claim 9

The method according to claim 6 wherein unbound sample materials and unbound specific binding materials are removed from the reaction zone by means of a wash step.

Claim 10

The method according to claim 6 wherein said liquid absorption means is located adjacent to said chromatographic material and offset downstream from said reaction site.

Claim 11

The method according to claim 6 wherein said reaction site includes an immobilized member of a signal generating substrate/cofactor group, said method further comprising the step (c′) of contacting one or more additional members of said signal generating substrate/cofactor group to said reaction site to initiate a signal generating reaction.

Claim 12

The method according to claim 9 wherein nitroblue tetrazolium is immobilized at said reaction site and bromochloroindolyphosphate is added to initiate a signal generating reaction.