Electrochemical metabolic activity detecting device

• US 10,449,542 B2
• Filed: 10/28/2015
• Issued: 10/22/2019
• Est. Priority Date: 10/28/2014
• Status: Active Grant

• Current Assignee: The Governing Council of the University of Toronto (University of Toronto)
• Original Assignee: The Governing Council of the University of Toronto (University of Toronto)
• Inventors: Kelley, Shana Olwyn, Sargent, Edward Hartley, Besant, Justin David
• Primary Examiner(s): Sines, Brian J.
• Application Number:
  US15/523,131
• Publication Number:
  US 20190046984A1
• Time in Patent Office: 1,455 Days
• Field of Search: 422 681, 422502, 422503, 422 8202, 422 8201, 436 43, 436 63
• CPC Class Codes: B01L 2200/0668 Trapping microscopic beads
• CPC Class Codes: B01L 2200/0673 Handling of plugs of fluid surrounded by immiscible fluid
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 2300/0681 Filter
• CPC Class Codes: B01L 2300/0816 Cards, e.g. flat sample carriers usually with flow in two horizontal directions
• CPC Class Codes: B01L 2300/0864 comprising only one inlet and multiple receiving wells, e.g. for separation, splitting
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 2400/0633 with moving parts
• CPC Class Codes: B01L 3/502761 specially adapted for handling suspended solids or molecules independently from the bulk fluid flow, e.g. for trapping or sorting beads, for physically stretching molecules investigating characteristics of particles G01N15/00
• CPC Class Codes: C12Q 1/02 involving viable microorganisms
• CPC Class Codes: G01N 1/40 Concentrating samples
• CPC Class Codes: G01N 33/48735 Investigating suspensions of cells, e.g. measuring microbe concentration by chemical means C12Q1/04; colony counters C12M1/34; concentration of particle suspensions in general G01N15/06
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80
• CPC Class Codes: G01N 33/493 urine
• CPC Class Codes: G01N 33/5005 involving human or animal cells immunoassay G01N33/56966; immunoassays of protozoa G01N33/56905; protozoa in screening assays C12Q1/025

Abstract

Methods and devices for detecting metabolic activity of target cells in a sample. The target cells are concentrated in a nanoliter well having a microfilter. A reporter compound that exhibits a change in electrochemical state in response to metabolic activity of the target cells is introduced. Metabolic activity or viability of the target cells is detected based on a determined change in the electrochemical state of contents in the well.

Claims

1. A method for detecting metabolic activity of target cells in a sample, the method comprising:

concentrating the target cells in a nanoliter well;

introducing into the well a reporter compound that exhibits a change in electrochemical state in response to metabolic activity of the target cells;

determining any change in an electrochemical state of contents in the well over a time period; and

detecting metabolic activity or viability of the target cells based on a determined change in the electrochemical state of contents in the well.

2. The method of claim 1 wherein the target cells comprise at least one of:

bacteria, mammalian cells, or fungi.

3. The method of claim 1, wherein the sample is a biological fluid.

4. The method of claim 3, wherein the biological fluid is one of:

urine, blood, plasma, or sputum.

5. The method of claim 1, wherein the sample is one of:

water or a buffer.

6. The method of claim 1 wherein the reporter compound is one of:

resazurin, methylene blue, formazan, or tetrazolium salts.

7. The method of claim 1, further comprising:

incubating the sample over at least a portion of the time period.

8. The method of claim 1, further comprising:

estimating an amount of the target cells in the sample based on the detected metabolic activity or viability.

9. The method of claim 1, further comprising:

prior to determining any change in the electrochemical state of contents in the well, introducing an antibiotic to the sample; and

determining any susceptibility of the target cells to the antibiotic based on the determination of metabolic activity or viability.

10. The method of claim 1, wherein concentrating the sample comprises:

introducing the sample into a device comprising the nanoliter well, the nanoliter well comprising;

an inlet for receiving the sample;

a microfilter for inhibiting the target cells from exiting the well through an outlet of the well; and

electrodes in the well for sensing the electrochemical state of contents in the well.