Test apparatus and methods for ST2 cardiac biomarker

• US 10,325,682 B2
• Filed: 09/11/2018
• Issued: 06/18/2019
• Est. Priority Date: 12/11/2014
• Status: Active Grant

• Current Assignee: Critical Care Diagnostics Inc.
• Original Assignee: Critical Care Diagnostics Inc.
• Inventors: Snider, James V., Bender, Jillian Elizabeth, Kuo, Shrin P., Chung, Roy A.
• Primary Examiner(s): Gabel, Gailene
• Application Number:
  US16/127,456
• Publication Number:
  US 20190013100A1
• Time in Patent Office: 280 Days
• CPC Class Codes: A61B 90/98 using electromagnetic means, e.g. transponders
• CPC Class Codes: G01N 2333/7155 for interleukins [IL]
• CPC Class Codes: G01N 33/5302 Apparatus specially adapted for immunological test procedures
• CPC Class Codes: G01N 33/54387 Immunochromatographic test strips
• CPC Class Codes: G01N 33/54388 based on lateral flow
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G16H 10/40 for data related to laboratory analysis, e.g. patient specimen analysis
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16Z 99/00 Subject matter not provided for in other main groups of this subclass

Abstract

The technology described in this document can be embodied in a test strip for use in measuring a level of an ST2 cardiac biomarker in a blood plasma sample. The test strip includes a base, and a plurality of conjugates, wherein each conjugate includes a reporter group bound to a first antibody that binds to ST2. A conjugate pad disposed along a length of the base and is configured to hold the plurality of conjugates that bind with ST2 to produce conjugate-ST2 complexes. The conjugate pad is further configured to receive the blood plasma sample. The test strip also includes a plurality of second and third antibodies that bind to ST2, and the conjugate-ST2 complexes, respectively. The plurality of second antibodies are bound to a membrane in a test location and the plurality of third antibodies are bound to the membrane in a control location.

Claims

1. A test system for ST2 cardiac biomarker, comprising:

a test strip configured to facilitate detection of a threshold level of ST2 in blood plasma;

a housing for the test strip, wherein the housing comprises;

a first section comprising an outer face and an inner face, wherein the inner face of the first section comprises a channel to receive the test strip along the length of the first section, and

a second section comprising an outer face and an inner face, wherein the second section is configured to be attached to the first section such that in an attached configuration the inner face of the first section faces the inner face of the second section, and the first and second sections together enclose the test strip within the housing, wherein the second section comprises;

a buffer port configured to allow a buffer solution to be dispensed to a portion of the test strip proximate to a first end of the test strip,

a test window configured to facilitate imaging of one or both of a test location and a control location on the test strip,

a sample port disposed between the buffer port and the test window, the sample port configured to enable a sample of blood plasma to be dispensed to the test strip, and

a set of projections disposed on the inner face of the second section between the test window and the sample port such that in the attached configuration, each projection in the set of projections is in contact with the test strip, wherein a height of at least one projection in the set of projections is different from a height of another projection in the set of projections, and heights of the different projections are configured such that, in the attached configuration, the set of projections produces a pressure gradient within the test strip that allows a fluid to flow at a predetermined flow rate along the length of the test strip between the first and last projections in the set of projections;

an identification tag disposed on or within the housing, wherein the identification tag is configured to store identification information about a patient or sample associated with the test strip; and

a reader device configured to accept at least a portion of the housing within the reader device, the reader device comprising an optical system that images one or both of the test location and the control location on the test strip, and displays an estimated level of ST2 in the sample of blood plasma.

2. The test system of claim 1, wherein the reader device is configured to query the identification tag to obtain at least a portion of the stored identification information.

3. The test system of claim 1, wherein the predetermined flow rate is such that the fluid flows from a portion of the test strip adjacent to the buffer port of the second section to a portion of the test strip adjacent to the test window of the second section in about 20 minutes.

4. The test system of claim 1, wherein the set of projections is a set of ridges.

5. The test system of claim 4, wherein distances between ridges are substantially equal.

6. The test system of claim 4, wherein the set of projections includes four ridges, a first ridge being disposed closer to the sample port than the other ridges, a fourth ridge being disposed closer to the test window than the other ridges, and a second ridge and a third ridge being disposed between the first and fourth ridges.

7. The test system of claim 1, wherein the first section includes multiple attachment projections that are configured to attach to corresponding attachment receptacles disposed on the second section, wherein dimensions of the attachment projections and attachment receptacles are configured such that in the attached configuration, the set of projections produces the pressure gradient that allows the fluid to flow at the predetermined flow rate along the length of the test strip.

8. The test system of claim 1, wherein the test strip comprises:

a base;

a plurality of conjugates, each conjugate comprising a reporter group bound to a first antibody that binds to ST2;

a conjugate pad disposed along a length of the base, wherein the conjugate pad includes the plurality of conjugates that bind with ST2 to produce conjugate-ST2 complexes, and wherein the conjugate pad is configured to receive the blood plasma sample;

a plurality of second antibodies that bind to ST2; and

a plurality of third antibodies that bind to the conjugate-ST2 complexes; and

a membrane disposed on the base such that the membrane is in fluid communication with the conjugate pad,

wherein the plurality of second antibodies are bound to the membrane in a test location and the plurality of third antibodies are bound to the membrane in a control location arranged further from the conjugate pad than the test location.

9. The test system of claim 8, wherein either the first or the second antibodies bind specifically to ST2.

10. The test system of claim 8, wherein both the first and second antibodies bind specifically to ST2.

11. The test system of claim 8, further comprising an absorbent pad disposed on the base, and in fluid communication with the membrane at an end or side of the membrane opposite the conjugate pad, wherein the absorbent pad is configured to absorb plasma and buffer that has traversed through the membrane.

12. The test system of claim 8, wherein the conjugate pad is disposed on the base to receive a buffer solution.

13. The test system of claim 8, wherein the conjugate pad comprises fibers comprising glass, polyester, or both glass and polyester.

14. The test system of claim 8, wherein at least one of the conjugate pad or the membrane comprises nitrocellulose.

15. The test system of claim 8, wherein the first antibodies are monoclonal antibodies.

16. The test system of claim 8, wherein the reporter group comprises fluorescent particles.

17. The test system of claim 8, wherein the third antibodies are goat anti-mouse IgG antibodies.