Volume independent diagnostic device
First Claim
1. A device for metering a constant volume of a liquid to an analyte assay area and for determining analyte concentrations in liquid samples consisting essentially of a first bibulous matrix devoid of reagent;
- a second bibulous matrix containing a suitable test reagent in a sufficient quantity for interaction with a particular analyte constituent of the liquid to produce a detectable change in the second bibulous matrix upon contact with the liquid, said second bibulous matrix being disposed sufficiently close to the first bibulous matrix and so positioned and sized that the interaction between the analyte constituent of the liquid and the testing reagent is quantitatively detected; and
a liquid impermeable barrier disposed over a portion but not all of the first bibulous matrix and at least a portion of the second bibulous matrix such that liquid applied to the first bibulous matrix at an area spaced from the second bibulous matrix will be metered into the second bibulous matrix only to the point of liquid saturation of the second bibulous matrix such that the quantitative determination of the analyte constituent of the liquid is independent of the volume of liquid sample applied to the first bibulous matrix.
2 Assignments
0 Petitions
Accused Products
Abstract
A process and device for quantitative determination of analyte concentrations in liquid samples. The device includes one or more bibulous matrices constructed and arranged to essentially eliminate sample volume sensitivity from analyte determinations. In accordance with the present invention, the device includes one or more test reagent-treated bibulous matrices covered at least partially by an impermeable coating or film. A liquid sample is applied to the uncovered portion of the bibulous matrix such that the liquid sample is metered into the bibulous matrix by the impermeable coating or film. The sample chromatographs through the bibulous matrix until the matrix is saturated with liquid. The process is essentially sample volume independent, providing more uniform and accurate quantitative analyte determinations.
-
Citations
11 Claims
-
1. A device for metering a constant volume of a liquid to an analyte assay area and for determining analyte concentrations in liquid samples consisting essentially of a first bibulous matrix devoid of reagent;
- a second bibulous matrix containing a suitable test reagent in a sufficient quantity for interaction with a particular analyte constituent of the liquid to produce a detectable change in the second bibulous matrix upon contact with the liquid, said second bibulous matrix being disposed sufficiently close to the first bibulous matrix and so positioned and sized that the interaction between the analyte constituent of the liquid and the testing reagent is quantitatively detected; and
a liquid impermeable barrier disposed over a portion but not all of the first bibulous matrix and at least a portion of the second bibulous matrix such that liquid applied to the first bibulous matrix at an area spaced from the second bibulous matrix will be metered into the second bibulous matrix only to the point of liquid saturation of the second bibulous matrix such that the quantitative determination of the analyte constituent of the liquid is independent of the volume of liquid sample applied to the first bibulous matrix. - View Dependent Claims (2, 3)
- a second bibulous matrix containing a suitable test reagent in a sufficient quantity for interaction with a particular analyte constituent of the liquid to produce a detectable change in the second bibulous matrix upon contact with the liquid, said second bibulous matrix being disposed sufficiently close to the first bibulous matrix and so positioned and sized that the interaction between the analyte constituent of the liquid and the testing reagent is quantitatively detected; and
- 4. A volume independent diagnostic device comprising at least one bibulous matrix, said bibulous matrix comprising a reagent-treated test area and an area devoid of reagent, the reagent-treated test area of the bibulous matrix being covered by a liquid impermeable barrier, said barrier so positioned to meter a liquid from the test area devoid of reagent to the regent treated test area of the bibulous matrix, wherein bibulous matrix area devoid of reagent permits liquid to pass through the bibulous matrix area devoid of reagent to introduce a constant, saturating amount of liquid into the reagent treated test area.
-
7. A method of determining analyte concentrations in a liquid comprising contacting a first area of a bibulous matrix devoid of reagent with an excess quantity of the liquid, said first area of said bibulous matrix disposed in contact with a second area of bibulous matrix, said second area containing a sufficient quantity of a suitable testing reagent for a particular analyte for interaction with the liquid to produce a detectable change in the second area of the bibulous matrix;
- said first area of the bibulous matrix and the second area of the bibulous matrix being only partially covered by a liquid-impermeable covering disposed to prevent the liquid from initially contacting an upper surface of the second area of the bibulous matrix, said covering metering the liquid from the first area of the bibulous matrix, under the liquid-impermeable covering to saturate the second area of the bibulous matrix to cause the liquid to interact with the testing reagent resulting in a detectable change in the second area of the bibulous matrix, and detecting the detectable change in said second bibulous matrix in the second area of the bibulous matrix.
- View Dependent Claims (8, 9)
-
10. A device for metering a constant volume of a liquid to an analyte assay area comprising a bibulous matrix having upper and lower major surfaces, the lower major surface disposed against a hydrophobic substrate, and the upper major surface being only partially covered by a liquid impermeable barrier, said bibulous matrix having a first portion devoid of reagent and a second portion which is reagent impregnated such that liquid applied to an area of the upper bibulous matrix surface spaced from the liquid-impermeable barrier is metered into the first bubulous matrix portion devoid of reagent, wherein the liquid flows through the first bibulous matrix portion devoid of reagent to saturate the second reagent impregnated bibulous matrix portion in the analyte assay are with a constant volume of liquid per unit volume of the second regaent impregnated bibulous matrix portion.
-
11. A method of introducing a constant volume of a liquid from a liquid application area to an assay area of a diagnostic device comprising contacting a bibulous matrix devoid of reagent with a quantity of liquid at least sufficient to saturate an assay area of the bibulous matrix containing regent, wherein a liquid-impervious covering is disposed over only a portion of the liquid-application area of the bibulous matrix which is devoid of reagent and over all or a portion of the assay area of the bibulous matrix containing reagent to prevent the liquid from initially contacting the assay area of said bibulous matrix containing reagent and to meter the liquid from the liquid application area to the assay area of said bibulous matrix containing reagent, allowing a quantity of the liquid to flow through said bibulous matrix devoid of reagent and under the liquid-impervious covering, to saturate the assay area of the blibulous matrix containing reagent.
Specification