# US 2012/0073969 A1 · Amelioration of Heterophile Antibody Immunosensor Interference

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- Number: US 2012/0073969 A1
- Document ID: US20120073969A1
- Status: Published application
- Kind: A1
- Application number: 13/312,302
- Filed: 2011-12-06
- Published: 2012-03-29
- Earliest claimed: 2009-03-25
- Assignees: Abbott Point of Care Inc.
- Inventors: John Lewis Emerson Campbell; John Emegbero Omakor
- Web page: https://patentgrep.com/patent/US20120073969A1

## CPC

- G01N 33/5306: {Improving reaction conditions, e.g. reduction of non-specific binding, promotion of specific binding}
- G01N 2333/4712: Muscle proteins, e.g. myosin, actin, protein
- G01N 2333/58: Atrial natriuretic factor complex; Atriopeptin; Atrial natriuretic peptide [ANP]; Brain natriuretic peptide [BNP, proBNP]; Cardionatrin; Cardiodilatin
- Y10S 436/824: Immunological separation techniques
- Y10S 436/825: Pretreatment for removal of interfering factors from sample
- Y10T 436/112499: with sample on test slide
- Y10T 436/25125: Digestion or removing interfering materials
- Y10T 436/25375: Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The invention is directed to methods and devices for reducing interference from heterophile antibodies in an analyte immunoassay. In one embodiment, the invention is to a method comprising the steps of (a) amending a biological sample such as a whole blood sample with non-human IgM or fragments thereof by dissolving into said sample a dry reagent to yield a non-human IgM concentration of at least about 20 μg/mL or equivalent fragment concentration; and (b) performing an electrochemical immunoassay on the amended sample to determine the concentration of said analyte in said sample. Preferably, the sample is amended with IgG or fragments thereof in addition to the IgM of fragments thereof.

## Claims

### Claim at position 1

1-29. (canceled)

### Claim 30

A device for performing an immunoassay of an analyte in a blood sample with reduced interference from heterophile antibodies, comprising a housing, an electrochemical immunosensor, a conduit and a sample entry port, wherein said conduit permits a blood sample to pass from the entry port to said immunosensor, and wherein at least one of said housing, said entry port, and said conduit includes a dry reagent comprising non-human IgM or fragments thereof and optionally IgG or fragments thereof, said dry reagent being capable of dissolving into said blood sample to yield an IgM concentration of at least about 20 μg/mL or equivalent fragment concentration and substantially sequestering any heterophile antibodies in said sample.

### Claim 31 (depends on 30)

The device of claim 30, wherein the dry reagent comprises non-human IgM or fragments thereof and IgG or fragments thereof.

### Claim 32 (depends on 31)

The device of claim 31, further comprising a metering system for metering an initial blood sample to form a metered blood sample.

### Claim 33 (depends on 31)

The device of claim 31, further comprising an immuno-reference sensor.

### Claim 34 (depends on 31)

The device of claim 31, wherein the analyte is a cardiovascular marker.

### Claim 35 (depends on 31)

The device of claim 31, wherein the immunoassay is for an analyte selected from the group, TnI, TnT, CKMB, myoglobin, BNP, NT-proBNP, proBNP, beta-HCG, TSH, D-dimer, and PSA.

### Claim 36 (depends on 31)

The device of claim 31, wherein the sample is amended for a predetermined period in the range from of about 1 minute to about 30 minutes.

### Claim 37 (depends on 31)

The device of claim 31, wherein the device is a single-use cartridge.

### Claim 38 (depends on 31)

The device of claim 31, wherein the dry reagent further comprises an enzyme-labeled antibody to the analyte.

### Claim 39 (depends on 31)

The device of claim 31, further comprising a second dry reagent comprising an enzyme-labeled antibody to the analyte, wherein the second dry reagent is separate from the dry reagent that comprises the IgM or fragments thereof.

### Claim 40 (depends on 31)

The device of claim 31, wherein the dry reagent further comprises a component selected from the group consisting of buffer, salt, surfactant, stabilizing agent, a simple carbohydrate, a complex carbohydrate and combinations thereof.

### Claim 41 (depends on 31)

The device of claim 31, wherein the non-human IgG or fragments thereof and IgM or fragments thereof are murine, caprine or a combination thereof.

### Claim 42 (depends on 31)

The device of claim 31, wherein the immunosensor performs an electrochemical enzyme-linked sandwich immunoassay.

### Claim 43 (depends on 31)

The device of claim 31, wherein the immunosensor comprises an immobilized antibody to the analyte on an electrode.

### Claim 44 (depends on 31)

The device of claim 31, wherein the analyte is TnI, and wherein said dry reagent dissolves into the sample to give an IgM concentration of from about 20 to about 200 μg/mL and an IgG concentration of from about 50 to about 5000 μg/mL.

### Claim 45 (depends on 31)

The device of claim 31, wherein the analyte is TnI, and wherein said dry reagent dissolves into the sample to give an IgM concentration of from about 20 to about 60 μg/mL and an IgG concentration of from about 500 to about 1000 μg/mL.

### Claim 46 (depends on 31)

The device of claim 31, wherein the analyte is BNP, and wherein said dry reagent dissolves into the sample to give an IgM concentration of from about 20 to about 200 μg/mL and an IgG concentration of from about 50 to about 5000 μg/mL.

### Claim 47 (depends on 31)

The device of claim 31, wherein the analyte is BNP, and wherein said dry reagent dissolves into the sample to give an IgM concentration of from about 20 to about 60 μg/mL and an IgG concentration of from about 500 to about 1000 μg/mL.

### Claim 48 (depends on 31)

The device of claim 31, further comprising a wash fluid capable of washing said sample to a waste chamber.

### Claim 49 (depends on 31)

The device of claim 31, further comprising a wash fluid comprising a substrate capable of reacting at said immunosensor to form a product capable of electrochemical detection.

### Claim at position 22

50-66. (canceled)

### Claim 67

A device for performing an immunoassay of an analyte in a blood sample with reduced interference from heterophile antibodies, comprising a housing, an electrochemical immunosensor, a conduit and a sample entry port, wherein said conduit permits a blood sample to pass from the entry port to said immunosensor, and wherein at least one of said housing, said entry port, and said conduit includes a dry reagent comprising non-human IgM or fragments thereof and IgG or fragments thereof at a weight ratio greater than 0.004.

### Claim 68 (depends on 67)

The device of claim 67, wherein the weight ratio is greater than 0.02.

### Claim 69 (depends on 67)

The device of claim 67, wherein the weight ratio is greater than 0.05.