Method for quantitative NIR spectroscopic analysis

• US 5,536,664 A
• Filed: 05/09/1995
• Issued: 07/16/1996
• Est. Priority Date: 06/27/1994
• Status: Expired due to Term

• Current Assignee: Johnson & Johnson Clinical Diagnostics Inc. (Johnson & Johnson)
• Original Assignee: Johnson & Johnson Clinical Diagnostics Inc. (Johnson & Johnson)
• Inventors: Switalski, Steven C., Kissel, Thomas R.
• Primary Examiner(s): ALEXANDER, LYLE
• Application Number:
  US08/437,734
• Time in Patent Office: 434 Days
• Field of Search: 250/339.11, 250/341.8, 422/82.05, 422/68.1, 422/55, 422/56, 436/164, 436/171
• US Class Current: 436/171
• CPC Class Codes: B01L 3/508 rigid containers not provided for above
• CPC Class Codes: G01N 21/359 using near infrared light
• 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
• CPC Class Codes: G01N 33/525 Multi-layer analytical elements
• CPC Class Codes: G01N 35/04 Details of the conveyor system G01N35/021 - G01N35/028 take precedence
• CPC Class Codes: G01N 35/1002 Reagent dispensers

Abstract

There is disclosed a slide test element and method of assay that allows for detection of analytes in biological liquids without the use of any detection reagents. The method uses NIR spectroscopy and a test element comprising a support, and a substantially constant light-path defining layer comprising a diffusely-reflecting material that is a) sufficiently porous in all directions as to allow a liquid to spread uniformly in all directions, and b) homogeneously reflects at least 95% of NIR radiation.

Claims

1. A method of quantitatively analyzing an analyte of a biological sample by near infrared (NIR) reflective or scattering spectroscopic quantitative analysis, comprising the steps of:

a) placing an aliquot of sample onto a test element comprising, in overlying relation,

a support, and

a substantially constant light-path providing layer consisting essentially of a diffusely-reflecting material that i) is sufficiently porous in all directions as to allow a liquid to spread uniformly in all directions, and ii) homogeneously and diffusively reflects at least 95% of NIR radiation,

b) illuminating the sample within said test element with light of NIR wavelengths,

c) detecting light of such wavelength that is reflected or scattered by said test element, and

d) spectroscopically analyzing the detected light for signals that are characteristic of the analyte being analyzed, said test element being substantially free of reagents during said steps a)-d).

2. A method as defined in claim 1, wherein said step d) comprises comparing said signal against a calibrated model for the analyte of choice based on either the raw detected signal or derivatives thereof, to ascertain from said calibrated model the concentration of said analyte of choice.