Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/72—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving blood pigments, e.g. haemoglobin, bilirubin or other porphyrins; involving occult blood
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/96—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving blood or serum control standard
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N2496/00—Reference solutions for assays of biological material
  • G01N2496/15—Reference solutions for assays of biological material containing dyes to mimic optical absorption of, e.g. hemoglobin
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/10—Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/10—Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
  • Y10T436/102499—Blood gas standard or control
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/10—Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
  • Y10T436/103332—Bilirubin or uric acid standard or control
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/10—Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
  • Y10T436/106664—Blood serum or blood plasma standard or control

Definitions

• This invention is in the field of spectrophotometric determinations of concentrations of substances in solution and relates to a quality control (QC) material for monitoring instrument precision on a daily basis.
• QC quality control
• the QC material is used to monitor instruments which are used to screen for serum or plasma specimen quantities of various interferents, by measurement of the near infrared (NIR) radiation and the adjacent visible radiation transmitted through a sample in a labelled tube, a pipette tip, or any similar material through which radiation can pass.
• the material can also serve as calibrators.
• An apparatus or instrument used for measuring interferents in serum and plasma i.e., assess specimen integrity is a substitute for visual inspection.
• the interferents may be regarded as analytes, with respect to the instrument used to measure the interferents. Because quantitative results from the determination of the concentration of such interferents are reported based on specific calibration algorithms, there is a need to monitor calibration performance daily.
• Internal quality control is a process used by all clinical laboratories for monitoring instrument calibration performance, particularly precision or reproducibility. It involves testing a stable material for the analyte(s) in question on a daily basis, and establishing target values for each analyte(s).
• concentrations of the interferents can be assigned to the QC material, and their predicted and assigned values can be used to adjust the initial calibration algorithms.
• recalibration a series of 3 to 5 QC samples with assigned analyte concentrations (may be regarded as calibrators), can be used to make calibration adjustments; recalibration is not a simple process, and adjustment of the initial calibration for biases may be preferred.
• the present invention provides a material which is able to allow for monitoring the calibration of spectrophotometric instruments which are used to measure concentrations of interferents using near infrared radiation and the adjacent visible radiation, and at the same time is stable at room temperature for a considerable period of time.
• the material can also be used to make calibration adjustments for biases, when necessary. This is also regarded as recalibration..
• the invention provides a quality control material for monitoring the calibration of instruments used to screen for interferents in serum or plasma specimens.
• the invention provides a quality control material to monitor the instrument calibrations for hemolysis, turbidity, bilirubinemia and biliverdinemia, either separately, or any two, or any three, or all four simultaneously, depending on the make-up of the quality control material.
• the material does not contain any blood products such as plasma lipids, bile pigments, or hemoglobin, is stable at room temperature, and is ready for use with up to four constituents.
• the invention provides a material and a method for monitoring the calibration of instruments used to screen for interferents in serum or plasma specimens using the quality control material of this invention.
• the invention provides a material and a method for adjusting the calibrations for biases, by using the slope and intercept of the linear regression equation obtained by plotting the assigned values of the respective interferents on the x-axis, and the predicted values, based on the original calibration algorithms, on the y-axis. This procedure is regarded herein as recalibration.
• the invention provides a substance with an absorbance spectrum which mimics the combined presence of hemoglobin, turbidity, bilirubin, and biliverdin at selected wavelengths in the 490 to 1085 nm region, and which combination of up to four substances provides a consistent stable composition.
• the invention relates to a composition containing amaranth, titanium dioxide, and methyl orange and biliverdin dihydrochloride.
• This composition is preferably prepared in a phosphate buffered saline and pH adjusted to about 7.4.
• a lipid emulsion of any source commercially available e.g., IntralipidTM (IL)
• IL IntralipidTM
• methylene blue can be used in place of biliverdin dihydrochloride
• 10 millimoles per liter sodium bicarbonate must be used instead of the phosphate buffered saline.
• the latter can be sterilized by autoclaving.
• the amaranth is used to mimic hemoglobin
• the titanium dioxide or IL is used to mimic turbidity
• methyl orange is used to mimic bilirubin
• the methylene blue is used to mimic biliverdin.
• Other dyes may be used, for example, phenol red or basic fuchsin may be used to mimic hemoglobin; phenol red at acidic pH's or amaranth at slightly higher pH may be used to mimic bilirubin; azure, thionine, or toluidine blue O may be used in combination with amaranth, to mimic biliverdin.
• any substance which produces an absorbance pattern similar to the "apparent" absorbance in the region used by a calibration algorithm may be used.
• One such example is copper sulfate.
• Turbidity causes an increase in the "apparent" absorbance. Apparent absorbance is based on the fact that transmitted light is measured and converted to absorbance units, therefore an instrument cannot distinguish true absorbance from loss of light due to scattering. In some cases, turbidity produces absorbance which is inversely proportional to wavelength. Turbidity is monitored by the slope of the absorbance curve at a single wavelength, namely, in the region greater than 800 nm.
• the invention consists of amaranth, phenol red, copper sulfate, and toluidine blue 0, in 100 millimoles per liter acetate buffer, pH 3 to 4.
• the amaranth can mimic both Hb and BR, making it possible to leave out phenol red.
• the pH of a given batch of QC material is maintained at a constant pH.
• Figure 1 is a graphic representation of the absorbance spectra of three different serum specimens, with added amount of interferents as shown.
• Figure 2 is a graphic representation of the absorbance spectra of three different mixtures of the quality control material, with predicted interferent concentrations as shown.
• g/L means grams per liter and mg/dL means milligrams per deciliter.
• Instruments designed to measure Hb as a measure of hemolysis, turbidity as an equivalent IL concentration, BR and BV, may require calibration adjustment or recalibration over a period of time.
• a material of the present invention with the following composition namely amaranth, phenol red, copper sulfate, and toluidine blue O, in 100 millimoles per liter acetate buffer, pH 3 to 4, can be used for monitoring such calibration.
• the concentrations of the substances will determine the assigned or target values of the analytes.
• such material may be used.
• any of such substances can be used alone or as a combination of two or three such substances, in any combination, depending upon the situation to be monitored, so long as the combination provides a consistent stable composition.
• the QC material was made by combining different amounts of stock solutions of amaranth, phenol red, copper sulfate, and toluidine blue O, dissolved in 100 millimoles per liter acetate buffer with pH values between 3 and 4; the change in pH changes the assigned values of the analytes.
• concentration of a stock solution will only serve as a guide to the amount of the stock which should be added to make a lot of QC material; the assigned or target value of an analyte will be determined by averaging the predicted concentrations of the interferents, using the appropriate calibration algorithm installed in the instrument used.
• target values must be assigned to lots with the same concentrations of "interferents", after sterilization; the predicted levels include any changes due to the sterilization process.
• sodium azide may be added; in respect of an embodiment the present invention with pH around 3 to 4, the acidic pH may be sufficient to prevent microbial growth.
• Different calibration algorithms may be developed for any one type of tube, pipette tip, or similar translucent material, and also algorithms may be developed for several different types of tubes combined or different translucent materials combined. The calibration algorithms installed in the instrument used to test the QC material of the present disclosure were developed for measurement in translucent pipette tips. These algorithms are as follows:
• Turbidity Algorithm g/L IL 296.01 (900nm) - 0.04 where (Xnm) is the raw absorbance measurement at the wavelength specified.
• Bilirubin Algorithm mg/dL BR 142.09 (511 nm) + 89.9 (554nm) - 4.47 where (Ynm) is the first derivative of the absorbance measurement at the wavelength specified.
• Biliverdin Algorithm mg/dL BV 160.29 (718nm) - 206.15 (781 nm) + 1.42 where (Znm) is the first derivative of the absorbance measurement at the wavelength specified.
• the serum specimens possessed varying degrees of hemolysis, turbidity, and bile pigmentation, and the QC specimens mimicked serum or plasma specimens with different levels of interferents.
• the present description has been concerned with a QC material containing four substances, it is to be understood that the QC material can be used to monitor calibration for any one, two, three, or all four interferents simultaneously.

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• 1996
  • 1996-06-12 GB GBGB9612264.3A patent/GB9612264D0/en active Pending
• 1997
  • 1997-06-12 US US09/147,373 patent/US6372503B1/en not_active Expired - Lifetime
  • 1997-06-12 WO PCT/CA1997/000418 patent/WO1997047972A1/en not_active Ceased
  • 1997-06-12 JP JP50101898A patent/JP4158056B2/ja not_active Expired - Fee Related
  • 1997-06-12 DE DE69732716T patent/DE69732716T2/de not_active Expired - Lifetime
  • 1997-06-12 EP EP97924842A patent/EP0975976B1/en not_active Expired - Lifetime

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