US 5,726,013 A · Reversible flow chromatographic binding assay system, kit, and method

Abstract

Disclosed are assay systems, kits, and methods for performing an assay which determines the presence or quantity of an analyte in a fluid sample by detecting binding of the analyte to at least one immobilized analyte capture reagent and washing unbound material from the immobilized analyte capture reagent. An elongated solid phase flow matrix includes: (i) a first region adapted for receipt of the fluid sample, (ii) a second region at which the analyte capture reagent is immobilized, (iii) a third region for application of a liquid wash and/or detector reagent capable of removing unbound substances from the second region; and (iv) an absorbent reservoir of high volume capacity. The second region is positioned between the first region and the third region and between the absorbent reservoir and the third region. The device also includes means to detect analyte bound at the second region. The fluid sample flows by capillary action initially along the elongated flow matrix in one direction toward and through the second region, and subsequently, liquid wash and/or detector reagent flows along the matrix in a second direction opposite the first direction, through the second region, and into the absorbent reservoir, drawing unbound substances with it.

Claims62

Dependent claims

An assay system for performing an assay which determines the presence or quantity of an analyte in a fluid sample suspected of containing the analyte by detecting analyte bound to an immobilized analyte capture reagent after unbound material has been washed away, the system comprising:

(a) an elongated solid phase flow matrix capable of driving fluid movement, the flow matrix comprising,
(i) a first matrix region for receipt of an analyte-containing fluid,
(ii) a second matrix region at which the analyte capture reagent is immobilized, the second matrix region being positioned in between the first matrix region and a third matrix region (iii),
(iii) the third matrix region being for receipt of liquid capable of removing from the second matrix region substances that are not bound to the analyte capture reagent;
and
(iv) an absorbent reservoir positioned to contact the matrix at an absorption region, the second matrix region being between the absorption region and the third matrix region;
(b) a mobile analyte binding reagent which is capable of:
i) binding to analyte;
ii) moving through the matrix;
and iii) facilitating detection of analyte bound to the second matrix region, said mobile analyte binding reagent comprising an analyte binding component and a detectable label;
whereby operation of the system initially causes movement of analyte-containing fluid in a first direction away from the first matrix region through the second matrix region;
and, after introduction of the liquid into the third region of the flow matrix and the absorbent reservoir is in contact with the absorption region of the matrix, flow in the matrix occurs in a second direction opposite the first direction, the second direction being away from the third matrix region and into the second region.

9 more elements

A kit for performing an assay which determines the presence or quantity of an analyte in a fluid sample suspected of containing the analyte by detecting analyte bound to an immobilized analyte capture reagent after unbound material has been washed away, the kit comprising the following elements (a) and (b):

(a) an assay device comprising the following elements (i) and (ii),
(i) an elongated solid phase flow matrix capable of driving fluid movement, the flow matrix comprising,
(A) a first matrix region for receipt of an analyte-containing fluid,
(B) a second matrix region at which the analyte capture reagent is immobilized, the second matrix region being positioned in between the first matrix region and a third matrix region (C),
(C) the third matrix region being for receipt of liquid capable of removing from the second matrix region substances that are not bound to the analyte capture reagent;
(ii) an absorbent reservoir of high volume capacity positioned for contact with the matrix at an absorbing position such that the second matrix region is between the absorbing position and the third matrix region;
(b) a mobile analyte binding reagent capable of moving through the matrix;
whereby operation of the kit initially causes movement of analyte-containing fluid mixture in a first direction away from the first matrix region and toward the second matrix region, so that at least a portion of analyte in the analyte-containing fluid mixture contacts and is bound to the immobilized analyte capture reagent;
and, after introduction of said liquid into the third region of the flow matrix, flow in the matrix is in a second direction opposite the first direction.

6 more elements

A method for performing an assay which determines the presence or quantity of an analyte in a fluid sample by detecting binding of the analyte to at least one immobilized analyte capture reagent and washing unbound material from the immobilized analyte capture reagent, the method comprising:

(a) providing
(i) an elongated solid phase flow matrix capable of driving capillary fluid movement, the flow matrix further comprising
(A) a first matrix region adapted for receipt of fluid comprising the analyte;
(B) a second matrix region at which the analyte capture reagent is immobilized, the second matrix region being positioned intermediate to the first region and a third matrix region (C);
(C) the third matrix region for application of a liquid reagent capable of removing unbound substances from the second region;
(ii) a reagent container which holds the liquid reagent;
(iii) a mobile analyte binding reagent which is capable of:
A) binding to analyte;
B) moving through the matrix;
and C) facilitating detection of analyte bound to the second matrix region, said mobile analyte binding reagent comprising an analyte binding component and a detectable label;
(iv) an absorbent reservoir positioned to contact the matrix at an absorption region, the second matrix region being between the absorption region and the third matrix region;
(b) applying a fluid comprising the analyte to the first matrix region;
(c) allowing the fluid to flow in a first direction through the second region, and then introducing the liquid reagent into the third matrix region and contacting the absorption region of the matrix with the absorbent rservoir, such that flow in the matrix is in a second direction, opposite to the first direction;
and
(d) detecting the analyte bound at the second region.

12 more elements

Dependencies are inferred from the claim text.

Reversible flow chromatographic binding assay system, kit, and method

Life of this patent

Reversible flow chromatographic binding assay system, kit, and method

Life of this patent

Abstract

Claims62