Method for reducing effect of hematocrit on measurement of an analyte in whole blood, and test kit and test article useful in the method

• US 20040157275A1
• Filed: 02/02/2004
• Published: 08/12/2004
• Est. Priority Date: 02/11/2003
• Status: Active Grant

• Current Assignee: Ascensia Diabetes Care Holdings AG (PHC Holdings Corporation)
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Marfurt, Karen L.
• Granted Patent: US 7,323,315 B2
• Time in Patent Office: Days
• US Class Current: 435/7.21
• CPC Class Codes: G01N 15/0205 by optical means
• CPC Class Codes: G01N 2015/012 Red blood cells
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/8483 Investigating reagent band test-element handling not specific to a test method G01N33/4875; analytical elements specific to chemical analysis of biological material G01N33/52; autometer with reagent band G01N35/04

Abstract

A method for determining the presence and/or amount of an analyte in a sample of whole blood comprises the step of treating the sample with a nonlytic hypertonic salt composition to reduce the hematocrit by reducing the size of the red blood cells. In optical detection systems, the smaller red blood cells create greater scatter, which allows a more accurate correction to be applied in a dual-wavelength detection system. In electrochemical detection systems, as well as in optical detection systems, the smaller red blood cells provide less obstruction to the diffusion of analyte and reagents in the sample, to facilitate the reactions thereof.

Claims

1. A method for determining the presence and/or amount of an analyte in a sample of blood, the method comprising the steps of (a) providing a sample of blood for qualitative or quantitative determination of an analyte, (b) treating the sample with a nonlytic hypertonic salt composition to adjust the hematocrit of the sample, and (c) determining the presence and/or amount of analyte in the sample.

2. The method of claim 1 where said analyte is selected from the group consisting of glucose, cholesterol, triglycerides, ethanol, lactic acid, beta-hydroxy butyrate, ketone bodies, and fructosamine.

3. The method of claim 1 wherein the presence and/or amount of analyte in the sample is determined by an optical detection method.

4. The method of claim 3 wherein said optical detection method is selected from the group consisting of reflectance, absorbance, and transmittance.

5. The method of claim 3 wherein a first optical measurement is made at a wavelength at which the reading is a function of the analyte and the hematocrit, a second optical measurement is made at a wavelength at which the reading is not substantially a function of the analyte, and the reading of the first measurement is corrected in accordance with the reading of the second measurement.

6. The method of claim 1 wherein the presence and/or amount of analyte in the sample is determined by an electrochemical method.

7. The method of claim 6 wherein said electrochemical method is selected from the group consisting of amperometric and coulometric methods.

8. The method of claim 1 wherein said hypertonic salt composition comprises one or more organic salts, or one or more inorganic salts, or any combination thereof.

9. A test article for use in the method of claim 1, said test article adapted to receive said blood sample, said test article comprising said nonlytic hypertonic salt composition.

10. The test article of claim 9 wherein said article is a test strip.

11. The test article of claim 10 wherein said test strip is treated with said nonlytic hypertonic salt composition by a method selected from the group consisting of impregnating, coating, depositing, and printing.

12. The test article of claim 9 wherein said test article is a microfluidic device.

13. The test article of claim 12 wherein said microfluidic device comprises a chamber or well in which said hypertonic salt composition is deposited.

14. The test article of claim 12 wherein said nonlytic hypertonic salt composition is carried to said sample via a microchannel.

15. A test kit comprising the test article of claim 9.

16. A test kit comprising the test article of claim 10.

17. A test kit comprising the test article of claim 12.