Single-pad strip for an improved lateral flow assay and a test device using the same
Inventors
KIM, Hyeon Suk • KOO, Tae-Hee • Choi, Young Ho
Assignees
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Publication Number
US-9575056-B2
Publication Date
2017-02-21
Expiration Date
Abstract
The present invention relates to a strip for an improved lateral flow assay of a biological sample on a single plane and a lateral flow chromatography assay using a test device containing the same. The strip of the present invention consists of a single-pad, which can improve lateral flow assay by providing an easy and simple procedure and clear visual reading. The strip of the present invention is consisted of sample application (sample) zone and reactant-resultant zone where the reaction mixture is deposited (reactant) are all on a same plane. In addition, the present invention provides a chromatographic method wherein hemoglobin is separated from analyte by a differential chromatography on the solid phase. Any interference of detection of the result by hemoglobin is removed by the present invention. The present invention provides advantages including an easy and simple procedure with a quick and clear response.
Core Innovation
The invention is a dry-format, single-pad lateral chromatographic assay strip in which a blood-lysing reagent and assay reagents are present on the same porous pad. A dry substrate in a reactant zone forms a precipitate when it reacts with a preselected analyte. The strip separates the analyte or its reaction resultant from hemoglobin by differential migration, with hemoglobin components migrating faster.
The described problem is that hemoglobin in blood can interfere visually with assay results. Differential migration allows the reaction product to be retained while hemoglobin moves farther along the pad, reducing this interference. Reported G6PD, lactate dehydrogenase, and alcohol assays produce stronger color signals on single-pad strips than on two-pad strips; the G6PD signal increases with enzyme activity.
Claims Coverage
The claims include one independent claim covering a single-pad lateral chromatographic assay strip, reciting five inventive features concerning the pad, blood lysis, differential migration, reaction resultant, and analyte scope.
Single-pad strip with a precipitating dry substrate
The strip consists of a single pad and a reactant zone impregnated with a dry substrate capable of forming a precipitate when reacted with the preselected analyte.
Blood-lysing pretreatment
The single pad is pretreated with a blood-lysing reagent, and red-blood cells in the blood sample are lysed upon contact with that reagent.
Differential migration from hemoglobin
The strip separates the preselected analyte or a reaction resultant from hemoglobin by differential migration. Hemoglobin components migrate faster than the preselected analyte or the reaction resultant.
Reaction product formed from the analyte and dry substrate
The reaction resultant is a reaction product generated by interaction between the preselected analyte and the dry substrate.
Analyte categories and sample fluids
The preselected analyte is selected from protein, carbohydrate, lipid, alcohol, and nucleic acid in a human or animal fluid.
The independent claim covers a single-pad strip that lyses red-blood cells and uses differential migration to separate hemoglobin from an analyte or its reaction product formed with a precipitating dry substrate.
Stated Advantages
Differential migration reduces visual interference from hemoglobin in the blood sample.
The reported G6PD, lactate dehydrogenase, and alcohol assays show stronger color signals on single-pad strips than on two-pad strips.
Documented Applications
The strip is described for enzyme-driven lateral chromatographic assays of preselected analytes, including proteins, carbohydrates, lipids, alcohols, and nucleic acids in human or animal fluid.
Reported assay examples include G6PD, lactate dehydrogenase, and alcohol testing.
The strip is presented for rapid point-of-care testing, including potential combined malaria and G6PD screening.
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