Materials for determining fructosamine levels in blood samples

• US 4,645,742 A
• Filed: 07/18/1984
• Issued: 02/24/1987
• Est. Priority Date: 12/23/1981
• Status: Expired due to Term

• Current Assignee: Roche Diagnostics Corporation (Roche Holding AG)
• Original Assignee: John R. Baker
• Inventors: Baker, John R.
• Primary Examiner(s): Turk, Arnold
• Assistant Examiner(s): Hill, Jr., Robert J.
• Application Number:
  US06/632,043
• Time in Patent Office: 951 Days
• Field of Search: 436/14, 436/15, 436/16, 436/67, 436/87, 436/88, 436/95, 436/111, 436/164, 436/63, 436/903, 436/904, 436/34, 436/63, 436/8, 422/61
• US Class Current: 436/15
• CPC Class Codes: G01N 33/66 involving blood sugars, e.g. galactose
• CPC Class Codes: Y10S 436/904 Oxidation - reduction indicators
• CPC Class Codes: Y10T 436/10 Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
• CPC Class Codes: Y10T 436/104998 Glucose, ketone, nitrate standard or control
• CPC Class Codes: Y10T 436/105831 Protein or peptide standard or control [e.g., hemoglobin, etc.]
• CPC Class Codes: Y10T 436/144444 Glucose

Abstract

The determination of fructosamine levels in at least part of a blood sample for use in detecting diabetes in patients or deciding treatment levels is effected by controlling the temperature and pH of the sample, adding a coloring agent such as a nitro-blue tetrazolium and after a first delay in time taking a first color measurment at a predetermined wavelength and after a second delay in time taking a second color measurement at the predetermined wavelength, then comparing any resultant change between the first and second color measurements with those of standard solutions, the selected timing delays, wavelength, coloring agent and pH conditions being such that any change of color in the coloring agent between the first and second color measurements is caused predominantly by the glucose in the sample that is reacted with an amine group of protein and has undergone a molecular rearrangement to form fructosamine and not materially by any non-specific reducing substance which may be present in the sample. Also disclosed are the reagent and standard solutions for use in the method of detecting fructosamine levels.

Claims

1. A reagent for use in determining serum fructosamine levels in a blood sample or a sample derived from blood, comprising a sufficient amount of an alkaline buffer and nitro-blue tetrazolium to convert any fructosamine present in a sample to its active enol form and react over time after the buffer and nitro-blue tetrazolium have been added to the sample such that any colour change after an initial period of time is caused predominantly by glucose in the sample that is reacted or associated with an amine group of protein and has undergone a molecular re-arrangement to form fructosamine and not materially by any non-specific reducing substances which may be present in the sample.

2. A standard solution for use in determination of serum fructosamine levels in a blood sample or a sample derived from blood, said standard solution comprising an aqueous solution of a protein and 1-deoxy-1-morpholinofructose.

3. The standard solution as claimed in claim 2 wherein said protein is albumin.