Abstract: An assay device includes: a detection zone which includes a first set of projections which are capable of generating capillary flow. A wicking zone (WZ) has a capacity to receive liquid sample flowing from the detection zone and includes a second set of projections which are capable of generating capillary flow. The WZ is rectangular in shape and the longer side of the rectangle extends in the direction of flow to thereby reduce the pressure gradient in the assay device which increases the total flow time of liquid sample compared to a WZ having equal length sides and same volume. At least a portion of the second set of projections have at least one dimension selected from a diameter, a center-to-center spacing, or a gap between projections that is different from the first set of projections, and is selected to increase the total flow time of the sample.

Abstract: An assay device includes: a liquid sample zone; a reagent zone downstream and in fluid communication with the sample zone containing a reagent material; a detection zone in fluid communication with the reagent zone having capture elements bound thereto; and a wicking zone in fluid communication with the capture zone having a capacity to receive liquid sample flowing from the detection zone. The sample receiving zone, the reagent zone, the detection zone and the wicking zone define a fluid flow path and at least a part of the fluid flow path has a substrate and projections which extend substantially vertically from the substrate, wherein the projections have a height, cross-section and a distance between one another that defines a space between the projections capable of generating capillary flow parallel to the substrate surface. In addition, the fluid flow path having projections includes a corner section which changes the direction of the flow path.

Abstract: An assay device includes: a detection zone which includes a first set of projections which are capable of generating capillary flow. A wicking zone (WZ) has a capacity to receive liquid sample flowing from the detection zone and includes a second set of projections which are capable of generating capillary flow. The WZ is rectangular in shape and the longer side of the rectangle extends in the direction of flow to thereby reduce the pressure gradient in the assay device which increases the total flow time of liquid sample compared to a WZ having equal length sides and same volume. At least a portion of the second set of projections have at least one dimension selected from a diameter, a center-to-center spacing, or a gap between projections that is different from the first set of projections, and is selected to increase the total flow time of the sample.

Abstract: An assay device for determining the concentration of multiple analytes or controls, where the device is capable of determining the presence or concentration of at least six analytes or controls includes: a fluid flow path; a liquid sample addition zone; a reagent zone downstream and in fluid communication with the sample addition zone containing one or more reagents; multiple detection zones in fluid communication with the reagent zone. The fluid flow path, which extends through the detection zones, has a length capable of having at least six detection zones linearly spaced at least a sufficient distance apart in order to discriminate each signal peak from its adjacent signal peak. The device further includes a wicking zone in fluid communication with the detection zones having a capacity to receive liquid sample flowing from the detection zone.

Abstract: An assay device includes: a liquid sample zone; a reagent zone downstream and in fluid communication with the sample addition zone containing a reagent material; a detection zone in fluid communication with the reagent zone. The detection zone has a substrate and projections which extend substantially vertically from the substrate, wherein the projections have a height, cross-section and a distance between one another that defines a capillary space between the projections capable of generating capillary flow parallel to the substrate surface. The device is capable of creating a reagent plume in the detection zone that includes liquid sample and dissolved reagent, where the width of the reagent plume extends substantially across the width of the detection zone, The device further includes a wicking zone in fluid communication with the detection zone having a capacity to receive liquid sample flowing from the detection zone.

Abstract: An assay device includes: a liquid sample zone; a reagent zone downstream and in fluid communication with the sample zone containing a reagent material; a detection zone in fluid communication with the reagent zone having capture elements bound thereto; and a wicking zone in fluid communication with the capture zone having a capacity to receive liquid sample flowing from the detection zone. The sample receiving zone, the reagent zone, the detection zone and the wicking zone define a fluid flow path and at least a part of the fluid flow path has a substrate and projections which extend substantially vertically from the substrate, wherein the projections have a height, cross-section and a distance between one another that defines a space between the projections capable of generating capillary flow parallel to the substrate surface. In addition, the fluid flow path having projections includes a corner section which changes the direction of the flow path.

Abstract: An assay device includes: a liquid sample zone; a reagent zone downstream and in fluid communication with the sample zone containing a reagent material; a detection zone in fluid communication with the reagent zone having capture elements bound thereto; and a wicking zone in fluid communication with the capture zone having a capacity to receive liquid sample flowing from the detection zone. The sample receiving zone, the reagent zone, the detection zone and the wicking zone define a fluid flow path and at least a part of the fluid flow path has a substrate and projections which extend substantially vertically from the substrate, wherein the projections have a height, cross-section and a distance between one another that defines a space between the projections capable of generating capillary flow parallel to the substrate surface. In addition, the fluid flow path having projections includes a corner section which changes the direction of the flow path.

Abstract: An assay device includes: a liquid sample zone; a reagent zone downstream and in fluid communication with the sample addition zone containing a reagent material; a detection zone in fluid communication with the reagent zone. The detection zone has a substrate and projections which extend substantially vertically from the substrate, wherein the projections have a height, cross-section and a distance between one another that defines a capillary space between the projections capable of generating capillary flow parallel to the substrate surface. The device is capable of creating a reagent plume in the detection zone that includes liquid sample and dissolved reagent, where the width of the reagent plume extends substantially across the width of the detection zone, The device further includes a wicking zone in fluid communication with the detection zone having a capacity to receive liquid sample flowing from the detection zone.

Abstract: A method of normalizing surface tension of a sample fluid on a clinical analyzer is disclosed. The method comprises aspirating a portion of a sample fluid into a metering tip, the metering tip having a lower end through which the sample fluid is aspirated and an upper end; sealing the lower end of the metering tip, forming a cuvette for the portion of the sample fluid; pre-treating a micro-tip with a surface tension-normalizing agent, and then dispensing the surface tension-normalizing agent into the sample fluid in the cuvette; mixing the surface tension-normalizing agent and the sample fluid in the cuvette using the micro-tip to create a mixture of the sample fluid and the surface tension-normalizing agent, the mixture having a normalized surface tension; and using the mixture for testing on the clinical analyzer.

Abstract: An assay element for analyzing a charged analyte employs an immobilized receptor and a material having a net charge which is the same as that of the analyte. In a preferred embodiment, the analyte is an aminoglycoside and the material is a polymer having a net positive charge.

Abstract: An assay element for analyzing a charged analyte employs an immobilized receptor and a material having a net charge which is the same as that of the analyte.