Patent ID: 9658223
Date: 2017-05-23
CPC Classifications: G01N

Claim:
1. A device for conducting an assay for the presence of a disease state in a subject, the disease characterized by the presence of an antigen in a sample from the subject, the device comprising: (a) a sub strate; (b) at least three lateral flow paths, each flow path formed by a porous fluid conducting medium on the substrate, wherein each fluid conducting medium includes a porous stratum overlying a hydrophobic layer; each flow path having an exterior end and an interior end; (c) a detection region, formed by a porous fluid retaining medium on the substrate; wherein the interior ends of the flow paths are fluidly coupled to the detection region and the detection region therefore lies at a junction of the flow paths, the fluid retaining medium including the same porous stratum overlying the same hydrophobic layer; and (d) first, second, and third load spots formed on the substrate, each load spot being at a corresponding one of the exterior ends of the flow paths and configured to receive an aqueous fluid; wherein the first load spot is configured to receive a sample from the subject, wherein the sample is to be assayed for presence of the antigen; wherein the detection region includes a first mixture of a first silk fibroin and a detection reagent including an antibody, the first mixture forming a first silk film in the detection region; wherein the second load spot includes a second mixture of a second silk fibroin and a secondary detection antibody that is released when the second load spot receives an aliquot of an aqueous compound, the second mixture forming a second silk film in the second load spot; and wherein the third load spot includes a third mixture of a third silk fibroin and a color reagent that is released when the third load spot receives the aliquot of an aqueous compound, and that causes a change in color in the detection region in the presence of a combination of the antigen, if contained in the sample, the primary and secondary detection antibodies, and the color reagent, the third mixture forming a third silk film in the third load spot; so that when the first load spot receives a sample from the subject that contains the antigen, and the second and third load spots are sequentially provided with aliquots of the aqueous compound, the components at each of the load spots sequentially react at the detection region after traversing the corresponding lateral flow paths to produce the change in color as an indicator of the presence of the antigen in the sample of the subject.