CA2053284C - Method for determination of glucose in whole blood and cuvette and photometer for carrying out said method - Google Patents

Method for determination of glucose in whole blood and cuvette and photometer for carrying out said method Download PDF

Info

Publication number
CA2053284C
CA2053284C CA002053284A CA2053284A CA2053284C CA 2053284 C CA2053284 C CA 2053284C CA 002053284 A CA002053284 A CA 002053284A CA 2053284 A CA2053284 A CA 2053284A CA 2053284 C CA2053284 C CA 2053284C
Authority
CA
Canada
Prior art keywords
sample
glucose
cuvette
reagent
photometer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
CA002053284A
Other languages
French (fr)
Other versions
CA2053284A1 (en
Inventor
Jan E. Lilja
Sven-Erik L. Nilsson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MIGRATA UK Ltd
Original Assignee
MIGRATA UK Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MIGRATA UK Ltd filed Critical MIGRATA UK Ltd
Publication of CA2053284A1 publication Critical patent/CA2053284A1/en
Application granted granted Critical
Publication of CA2053284C publication Critical patent/CA2053284C/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C12BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
    • C12QMEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS; COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES
    • C12Q1/00Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions
    • C12Q1/54Measuring or testing processes involving enzymes, nucleic acids or microorganisms; Compositions therefor; Processes of preparing such compositions involving glucose or galactose
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01Arrangements or apparatus for facilitating the optical investigation
    • G01N21/03Cuvette constructions
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/314Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry with comparison of measurements at specific and non-specific wavelengths
    • G01N2015/011
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01Arrangements or apparatus for facilitating the optical investigation
    • G01N21/03Cuvette constructions
    • G01N2021/0321One time use cells, e.g. integrally moulded
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01Arrangements or apparatus for facilitating the optical investigation
    • G01N21/03Cuvette constructions
    • G01N2021/0325Cells for testing reactions, e.g. containing reagents
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/01Arrangements or apparatus for facilitating the optical investigation
    • G01N21/03Cuvette constructions
    • G01N2021/0346Capillary cells; Microcells
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/17Systems in which incident light is modified in accordance with the properties of the material investigated
    • G01N21/25Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
    • G01N21/31Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
    • G01N21/314Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry with comparison of measurements at specific and non-specific wavelengths
    • G01N2021/3181Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry with comparison of measurements at specific and non-specific wavelengths using LEDs
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/75Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
    • G01N21/77Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator
    • G01N21/78Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated by observing the effect on a chemical indicator producing a change of colour
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2201/00Features of devices classified in G01N21/00
    • G01N2201/12Circuits of general importance; Signal processing
    • G01N2201/122Kinetic analysis; determining reaction rate
    • G01N2201/1222Endpoint determination; reaction time determination
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2201/00Features of devices classified in G01N21/00
    • G01N2201/12Circuits of general importance; Signal processing
    • G01N2201/126Microprocessor processing
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01NINVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/483Physical analysis of biological material
    • G01N33/487Physical analysis of biological material of liquid biological material
    • G01N33/493Physical analysis of biological material of liquid biological material urine

Abstract

A sample of whole blood is contacted with a reagent which by chemical reaction with glu-cose in the sample brings about a detectable dye concentration change (10) the size of which is de-termined as a measure of the glucose content of the sample. The sample is initially introduced un-diluted in a microcuvette having at least one cavi-ty for receiving the sample. The cavity is internal-ly pretreated with the reagent in dry form, and the chemical reaction takes place in the cavity.
Active components of the reagent comprise at least a hemolysing agent for exposing glucose contained in the blood cells of the sample for al-lowing total glucose determination, and agents taking part in tho chemical reaction and ensuring that the dye concentration change (10) takes place at least in a wavelength range (14) outside the absorption range (12) of the blood hemoglob-in. An absorption measurement is performed in said wavelength range directly on the sample in the cuvette. A pretreated disposable cuvette with such a reagent and a photometer are also de-scribed.

Description

'uD 90/12890 PCT/SE90/00273 ~~53284 METHOD FOR DETERMINATION OF GLUCOSE IN WHOLE BLOOD AND
CUVETTE AND PHOTOMETER FOR CARRYING OUTSAID METHOD
The present: invention relates to a method for quantitatively dletermining total glucose content in whole blood, and to a disposable cuvette and a photometer for carrying out the: method.
Determination of whole blood glucose is made for diagnosing and controlling diabetes, and also in endo-crinological investigations. In uncertain cases of uncon-ciousness, too, determination of whole blood glucose may be justified. Diabetes is one of the world's major health problems, and it is estimated that more than 40 million people suffer from this disease and that the prevalence of type II diabetes seems to increase.
Several methods for determining glucose are known.
Many old methods have today been abandoned because of unspecificity or the involvement of carcinogenic reagents.
By glucose .in blood, whole blood glucose, is meant non-protein-bound glucose present in trie blood. Glucose is freely distributed in the extracellular water and also in the intracellular water, e.g. in the red blood cells, but not necessarily :in the same concentration. This means that the total content of glucose in whole blood differs from the total content of glucose in plasma or serum. The diagnostic criteria far e.g. diabetes are predominantly based on whole blood glucose. To the clinician, it is therefore clearl;t advantageous to have the glucose deter-minations made d:Crectly on whole blood. The difference between determinations of glucose in whole blood and glucose in plasma or serum is discussed by W.T. Caraway:
Amer. J. Clin. Path. 37:445, 1962. Many glucose tests currently used, where intact red blood cells are removed, incorrectly state: their results as blood glucose and may therefore cause confusion in medical diagnosis because of the different references used.

WO 90/12890 ~ ~ ~ ~ ~ ~ ~~ PCT/SE90/002~2 Most of today's specific glucose determination methods are based on reagents containing enzymes or enzyme systems. Three different enzyme systems are predominant, viz. glucose oxidase, hexokinase and glucose dehydrogenase (GDH).
The present invention preferably relies on reagents containing glucose dehydrogenase (GDH). Previously known determination methods using GDH are described in US
4,120,755 and US 3,964,974. These prior art determination methods using GDH are traditional wet-chemical methods.
None of the above-mentioned methods is however suit-able for determining glucose in undiluted whole blood.
Although Example 7 in US 3,964,974 describes a whole blood glucose method, this method is based on dilution and pro-tein precipitation or separate hemolysis of the blood sample.
EP 84112835.8 describes a whole blood glucose method for undiluted blood. The chemical enzyme reaction used is based on glucose oxidase, and an optical reflectance mea-surement is carried out at a wavelength above 600 nm. It is well known that hemoglobin interferes with oxidase reactions. Also, oxidase reactions require access to free oxygen. Therefore, using a microcuvette for performing a whole blood glucose determination with the glucose oxidase system in undiluted blood involves substantial problems.
From US 4,088,448 is previously known a microcuvette which can be used for hemoglobin measurement (Hb measure-ment) of blood. The cuvette is pretreated with a reagent, such that when a blood sample is drawn into the cuvette, the walls of the red blood cells are dissolved and a chemical reaction is initiated, the result of which allows Hb determination by absorption measurement directly through the cuvette which, to this end, has an accurately defined gap width.
The method according to US 4,088,448 for Hb deter-mination on glucose is not easily applied in practice since an absorption measurement for determining the ""~O 90/12890 glucose content is strongly interfered with by the absorption caused by the hemoglobin. Variations in the hemoglobin concentration will therefore interfere with the glucose determination to a considerable extent.
Thus, present-day methods are complicated. They often require dilution of the blood sample or only perform a glucose determination on the blood plasma without taking into account the glucose contents of the red blood cells.
It is therefore evident that a simple, reliable and quick method for quantitatively determining the total content of glucoae in undiluted whole blood would be an important aid in diagnosing and controlling diabetes.
One object of the present invention is to provide a method for quant:Ctatively determining the total content of glucose in undiluted whole blood by transmission photo-metry. Another object is to provide a cuvette and a photo-meter for such determination.
Generally, i:he above-mentioned interference problem caused by the hemoglobin content is solved according to the invention in the following way:
By using a :>uitable reagent, it is possible first to cause the walls of the red blood cells to dissolve, and then to bring about a chemical reaction between the total glucose content of the blood sample and the reagent, which reaction yields chemical compounds which are based on the glucose and the absorption range of which, wavelengthwise, is at least partly outside the wavelength range of the hemoglobin absorption range. Thus, by absorption measure-ments at suitably selected wavelengths it is possible to completely eliminate the influence of the hemoglobin on the measuring result and to achieve very quick glucose determination.
Thus, the invention provides a method for glucose determination in whole blood, in which a sample of whole blood is contacted with a reagent which by chemical reac-tion with glucose in the sample brings about a dye con-centration change which is detectable in the sample and WO 90/12890 L ~ J ~ ~ ~ l ~ PCT/SE90/002~'~
the size of which is determined as a measure of the glucose content, the method being characterised by the steps of introducing the sample undiluted in a microcuvette having at least one cavity for receiving the sample, said cavity being internally pretreated with the reagent in dry form and said chemical reaction then taking place in said cavity, selecting as active components included in the reagent at least a hemolysing agent for exposing glucose contained in the blood cells of the sample for allowing a quantitative total glucose determination in a whole blood hemolysate, and agents participating in the chemical reac-tion and ensuring that the dye concentration change takes place at least in a wavelength range outside the absorp-tion range of the blood hemoglobin, and performing an absorption measurement at said wave-length range directly on the sample in the cuvette.
Preferred embodiments of the inventive method are stated in the subclaims 2-7.
According to a preferred embodiment of the invention, the method comprises the steps of supplying undiluted whole blood to a dry reagent in a cuvette having a small gap width including a hemolysing agent, GDH, diaphorase or analog thereof, NAD or analog thereof, detergent and a dye-forming substance, and photometrically measuring the concentration of dye formed by transmission measurement in a filter photometer. Diaphorase analogs are substances having redox properties of the type phenazine mettro-sulphate or phenazine ettrosulphate. These may replace diaphorase substances, but are unsuitable from the point of view of toxicity.
The glucose dehydrogenase method is specific to ~-glucose. In blood, a-glucose and ~-glucose exist in a temperature-dependent equilibrium. When lowering the temperature of a blood sample, the equilibrium is shifted towards a larger proportion of a-glucose. The change of ~~ 90/12890 2~53~8~~ '- PCT/SE90/00273 equilibrium is slow. The reaction speed of the glucose dehydrogenase method is affected by the enzyme mutarotase and, thus, the ac-glucose/p-glucose equilibrium. In blood glucose determination, it is essential that the analysis 5 is carried out without any delay to prevent inherent metabolism in th~a sample. Since the spontaneous a~~ reac-tion occurs very slowly and the body temperature is sufficiently conatant for ensuring the ac/~ equilibrium, mutarotase can advantageously be exc7.uded in the case of direct testing on body-temperature blood, yet allowing calibration of the photometer in total glucose. In addi-tion to the cost reduction, the advantages of the method reside in a decrE.ased reaction time and an extended analytical range" A disadvantage is that calibration and control solutions should be brought to proper temperature during at least .1 h.
According to a preferred embodiment of the invention, a reagent system of the glucose dehydrogenase type con-sists of a hemolysing agent for breaking up the red blood cells and liberating hemoglobin, GDH diaphorase or analog to make the NADH reaction visible, NAD or analog, deter-gent or a dye-foz-ming substance, e.g. taken from the group of tetrazolium compounds. In addition to these active sub-stances, other chemical substances can be used as produc-tion aids.
The absorbar.~ce by the hemoglobin liberated during hemolysis is described in E.J. van Kampen and W.G. Zi~lstra (1965): "Determination of hemoglobin and its derivations"
in Adv. Clin. Che:m. 8, 141-187, p 165, Fig. 12. It is seen from this figure that in case an absorption measurement occurs at a wavelength above 645 nm, the effect of any hemoglobin derivative is minimised.
Another type of interference in absorption measure-ments is e.g, particle scattering of the light from cells, fat, dust or other deficiencies. Hy measuring at another wavelength, often above the primary measuring wavelength, where neither hemoglobin nor the dye formed gives rise to WO 90/12890 ~- PCT/SE90/002~"
~3~~~~
any interfering absorbance, this background absorbance can be compensated for.
The reaction process of the glucose dehydrogenase system is well known and described in US 3,964,974. This publication reports on a reaction process comprising tetrazolium salt with absorption in the visible range.
An essential feature of the method according to the invention is the use of a glucose dehydrogenase reaction proceeding to end-point, both chemically and in respect of absorption photometry. In terms of safety and reliability, such a reaction is preferable to the user.
Optical methods for quantitative determination of the concentration of a chemical substance in a solution are well known and well documented. Absorption photometry is an optical determination technique. The theory behind absorption photometry and the design of a photometer are described in Skoog and West: "Fundamentals of Analytical Chemistry", Section Edition, Chapter 29. Basically, a photometer consists of three parts, an optical part, a mechanical part and an electronic part. The optical part consists of a light source with a monochromator or inter-ference filter and a light detector, and in some cases a lens system. The mechanical part comprises the suspension of the optical part and means for transporting cuvettes with chemical solution. The electronic part is designed for the control and monitoring of the light source and the measuring signals from light detectors, these signals being so processed that the user can read a numerical value which is related to or represents the chemical con-centration measured.
Such a photometer construction is disclosed in US
4,357,105. This patent describes a photometer for deter-mining hemoglobin in blood, which provides optimisation with known components, such that the photometric determi-nation occurs as close to the measuring wavelength 540 nm as possible. The adjustment to the measuring wavelength 540 nm is carried out by using a light emitting diode and 2~53~84 ~'O 90/12890 PCT/SE90/00273 a light filter of the didymium-oxide glass type. In an alternative embodiment, a light emitting diode is used within the infrared range for measuring turbidity in the chemical solution. This known photometer is intended to be used for ordinary wet-chemical hemoglobin determination methods, having a degree of dilution of 1/200 and above between blood and reagent.
A photometer for determining the glucose content in whole blood according to the method described, i.e.
supplying dry glucose reagent to undiluted blood and performing a photometric two-wavelength measurement on a microcuvette, must be simple, reliable and available at a low cost. Since i:he cuvette contains a dry glucose reagent, it is oi' the disposable type, and the transport of the cuvette, after filling with undiluted blood, must be uncomplicated and minimise the effect of stray light.
In terms of operation, the photometer must be photometrically stable and require a minimum of controlling.
Thus, in ordler to carry out the inventive method the invention further' provides a disposable cuvette according to claim 8 pretreated with a dry reagent, and a photometer according to claim 9 operating at two separate wave-lengths, preferred embodiments of the latter being stated in claims 10 and 11.
A photometer for carrying out the inventive method for measuring whole blood glucose in small volumes in undiluted blood by means of a microprocessor for monitor-ing and controlling and having arithmetic calculation capacity, as well as light emitting diodes provided with an interference filter, gives a construction which is easy to handle, technically stable and employs silicon elec-tronics throughout, has low power consumption, is highly reliable and can be manufactured at a low cost. If the mechanical part, 'the outer casing and the bottom as well as the cuvette transport means, including the part where the optical components are attached, is made of injection-WO 90/12890 PCT/SE90/002'-' 24~5~~~~
a moulded plastic, the overall production costs for the photometer will be low.
A microprocessor-assisted photometer is able to con trol all processes and carry out all calculations includ ing logarithmic transformations. The light emitting diodes of a photometer for two-wavelength measurements are pulsed via the microprocessor such that only one light emitting diode is lit at a time. Light emitting diodes are highly advantageous by having no afterglow. In order to ensure that the light emitting diodes do not lose their light intensity by ageing, the photometer is designed such that maximal light intensity, corresponding to 100$ light, is regularly measured between different cuvette measurements.
By designing the mechanical cuvette transport function such that the photometer can sense if a cuvette should be measured or if the total intensity, 100$ light, should be measured, the photometer can operate with a compensation for light intensity. By the possibility ~f establishing whether the measured value is a cuvette value or a blank value, 100$ transmission, the photometer can operate, by means of its microprocessor equipment, without any loga-rithmic analog amplifiers. The absence of logarithmic analog amplifiers increases the reliability and the sta-bility of the photometer while at the same time arbritary accuracy in the logarithmic operation is achieved by a logarithmic algorithm in the microprocessor program. A
further advantage of a microprocessor-assisted photometer is that different forms of arithmetic curve adaptations of calibration curves or linearisations can easily be introduced in the program. By the microprocessor function, it is also possible to use different forms of end-point routines, i.e. the program can itself decide when the end-point has been reached, which can be done with different accuracies for different concentration levels, where so desirable.

'~'O 90/12890 2~ J32~~PCT/SE90/00273 The inventj.on will now be described in more detail with reference t:o the accompanying drawings.
Fig. 1 is a graph with absorbance set against wave-length, both for a mix of hemoglobin derivatives and for a dye-forming substance included in a glucose reagent.
Figs. 2A, 3A and 4A show three different embodiments of an inventive ;photometer.
Figs. 2H, 3.B and 4H correspond to the embodiments of Figs. 2A, 3A and 4A, respectively, but include a separate logarithmic amplifier.
Fig. 5 schernatically shows a broken-apart section of an embodiment of the optical part of an inventive photo-meter.
Fig. 1 indicates by a full line 10 an absorption spec-trum for a tetraz:olium salt, 3-(4,5-dimethyl thiazolyl-1-2)-2,5-diphenyl. rtetrazoiium bromide (MTT), and by a dashed line 12 an absorption spectrum for hemolysed blood.
It is seen that above 500 nm there is a wavelength range where MTT can be quantitatively determined with a minimum of interference by hemoglobin. I:t also appears that com-pensation for background interference can occur at higher wavelengths. At two-wavelength measurements in absorption, it is essential to use wavelengths which are distinctly separated so as not to interfere with each other. The interference filters used in the filter photometer are defined wavelengthwise by the wavelength where maximal light transmission is obtained. zn addition, an inter-ference filter has a half bandwidth defined where a maximum of 50~ of the light transmission is obtained.
Figs. 2A, 3A, 4A and 2B, 3H, 4B show different embo-diments of a microprocessor-assisted photometer. Version 'A' in these Figures shows a photometer without a logarithmic amplifier, the logarithmic operation taking place in the program of the microprocessor. Version 'B' in these Figures makes use of a separate logarithmic ampli-fier 19. The use of a separate logarithmic amplifier 19 WO 90/12890 PCT/SE90/002'"' ~:~~J~ic~a~.
means simpler programs in the microprocessor, but poorer technical characteristics of the photometer.
Figs. 2A, 2B and 3A, 3B differ in that Figs. 3A, 3B
make use of a digital-to-analog converter 46 when passing 5 from analog to digital form. This arrangement has the advantage of being economical, but gives poorer stability by necessitating peripheral equipment.
The photometer in Figs. 2-4 physically consists of two structural blocks: one optical housing and one elec-10 tronic printed circuit board 16. The electronic printed circuit board is of standard type where the components used are applied by surface mounting or soldering in traditional manner in a drilled laminate board. In certain cases, it is possible to use a printed circuit board allowing a combination of different mounting techniques.
Tfie embodiment in Fig. 2A will now be described in more detail. A printed circuit board 16 included in the photometer is schematically shown by dash-dot lines and contains a microprocessor 18, an analog-to-digital con verter 20, a multiplexes 22, a potentiometer 24, an LCD
drive unit 26, an LCD display unit 28, a light emitting diode drive circuit 30, a mains rectifier 32, a battery charging circuit 34, and peripheral equipment (not shown) of a type known to a person skilled in the art.
The printed circuit board 16 is connected to the other photometer part comprising a cuvette housing 36, two light emitting diodes 38, a light sensor 40, and a switch 42.
In operation, the multiplexes 22 receives analog signals from the light sensor 40, from the battery charg-ing circuit 34 and from the potentiometer 24 and trans-mits, in accordance with control instructions 44 from the microprocessor 18, one of these signals to the analog-to-digital converter 20. This converts the signal to a form which can be handled by the processor 18 which depending on the signal received executes different operations.

2~~~32~4 J~'O 90/12890 PCT/SE9010027:~

The processor 18 receives the signal from the poten-tiometer 24, which is adjustable by the user, when the photometer is calibrated by means of a sample of known glucose content. In this way, a constant is established in the algorithm by means of which the glucose content is calculated on the basis of the transmittance measured.
The processor 18 receives the signal from the battery charging circuit 34 when the processor 18 should compen-sate for varying battery charge.
The processor I8 receives the digitilised measuring signal from the light sensor 40, both when measuring 100%
transmittance as reference, and when measuring trans-mittance through the blood sample in a disposable cuvette placed between t;he light emitting diodes 38 and the light sensor 40.
Dn the basis of a preprogrammed algorithm, the processor 18 calculates the glucose content of the sample and emits the re:~ult to the LCD drive circuit 26 for displaying it to the user on the I~CD display 28.
In Figs. 2H,, 3A and 3H as well as 4A and 4H, like parts, as in Fig., 2A, are represented by like reference numerals.
In the variant of Fig. 3A, the analog-to-digital con-verter in Fig. 2A is excluded and replaced by a combina-tion of a comparator 45, a digital-to-analog converter 46 and the microprocessor 18. The processor 18 emits to the converter 46 a digital value which is converted to analog form and which is successively changed by the processor 18 until a zero signal is obtained on the output of the comparator 45. Otherwise, the function is the same as in Fig. 2A.
The basic design of the optical housing appears from Fig. 5. The arrangement comprises two light emitting diodes 52, 64 disposed at 90° to each other. To obtain a similar optical a;~cis, the light emitting diodes should be adjusted prior to mounting.

"'O 90/12890 i~~~3~~~ PCf/SE90/002",=

A photometer for glucose in undiluted blood can have its measuring wavelength at 660 nm (at 14 in Fig. I). As a result of the measurement of the absorbance flank on the dye formed, the half bandwidth of the measuring wavelength must be well defined. The background wavelength for measuring glucose in undiluted blood should be above 700 nm. A suitable choice of background wavelength is where commercial light emitting diodes are available, e.g.
740-940 nm.
In Fig. 5, it is seen how a light ray 50 from a red light emitting diode 52 passes an interference filter 54 having maximal light transmission at 660 nm and a half bandwidth less than 15 nm, and through a mirror disposed at an angle of 45°. After the light ray 50 has passed the interference filter 54 and the mirror 56, it passes through the cavity 60 of the cuvette 58, which cavity con-tains undiluted whole blood and glucose reagent or glucose reagent products, and reaches the light detector 40 through an opening 53 in a cuvette holder 55. The light detector 40 can be provided with a small collecting lens 62.
The light ray from the infrared light emitting diode 64 is reflected on the rear side of the 45°-inclined mirror 56, passes through the cavity 60 of the cuvette 58 and reaches the detector 40. The infrared background wave-length is measured with the second light emitting diode 64 and on a plane absorbance level (e.g. at 15 in Fig. 1), the half bandwidth of the infrared light emitting diode 64 being of little importance.
If the cuvette transport device 55, e.g. a carriage construction, is equipped with an element that can be sensed by a stationarily arranged sensor, the micro-processor 18 can easily be supplied with information 43 about the position in which the cuvette 58 is situated. If a carriage 55 is used as cuvette conveyor, it may have a magnet which is sensed by two fixed magnetic reed relays.
When the carriage is in the extracted position for intro-'~'O 90/12890 ducing the cuvette 58, maximal light, 100 light, is measured.
Maximal light is measured for both measuring wave-length and background measuring wavelength. Hy continuous-ly calculating the quotient in per cent between measuring value, cuvette i:n measuring position and maximal light, good c:ompensatio;n for ageing phenomena in the light sourcea 52, 64 ins obtained in transmittance measurement. A
logarj.thmic operation on the transmission value is executed in the microprocessor 1$, or in a separate cir-cuit (see version 'B') for receiving a measure of absor-bance.
The current of the light detector 40 reaches an ope-rational arnplifiEar which converts current to voltage to permit easy proceassing of the signals on the printed circuit board 16.. The microprocessor i8 also monitors whether the dark current from the detector 40 is low and compensates for t:he influence of the dark current by taking this into account in the calculation formulae used.
In Figs. 2-4, there is only one movable part, viz.
the potentiometer 24. The potentiometer 24 is the only component which t:he user can operate on the printed circuit board 16. The potentiometer 24 is used for calibrating the photometer against blood of known glucose content. To achieve maximal stability, the other components of.the: photometer are preferably stationary.
For economic, reasons, the microprocessor is a one-chip processor. To save energy, the digit displays are of the LCD type and the photometer is supplied with energy from a mains transformer or a battery.
Fig. 4A shows another embodiment of the invention.
This version uses the programming possibilities of the microprocessor 18 for providing a photometer which is easier to trim and has enhanced stability. This is achieved in that the supply of current to the two light emitting diodes 3B is controlled through a digital-to-analog converter '70 which, in terms of programming, is in WO 90/12890 PCT/SE90/002~' 2~532~~

feedback with the measuring signal. It is then possible, in terms of measurement, to maintain the blank value, 100$
transmission, on a constant level. This constant level is electronically determined by the resolution (number of bits) in the digital-to-analog conversion.
Example A microcuvette 58 of the type described in the above-mentioned US 4,088,448 was provided by freeze-drying with a dry reagent for quantitative determination of total glucose in whole blood. The microcuvette was charged with dry reagent by producing, in a first step, a water-soluble reagent composition. The water-soluble glucose reagent composition consisted of (volume 1 ml):
100 units GDH, glut~se dehydrogenase units diaphorase 20 umol NAD
pmol MTT
20 25 mg White Saponin 1 ml water subjected to ion-exchange In step 2, the microcuvette was filled with about 5 ul reagent composition solution, the distance between the walls in the sample-absorbing cavity 60, which also 25 serves as analysing cavity, being about 0.14 mm .
In step 3, the microcuvette was freeze-dried. After step 3, the microcuvette contained a dry reagent for determination of glucose in undiluted blood uniformly distributed in the cavity 60. The microcuvette was then 30 ready for analysing.
A photometer of the type described above and equipped with a microprocessor 18 of the Intel 8751 type was provided with a suitable program for determining glucose in whole blood. The photometer was programmed in order, at end-point, to give results on glucose in whole blood expressed in mmol/1. The light emitting diodes 38 were

Claims (12)

1. Method for determining the glucose content in whole blood, in which a sample of whole blood is contacted with a reagent which by chemical reaction with glucose in the sample brings about a dye concentration change which is detectable in the sample and the size of which is determined as a measure of the glucose content, cha-racterised by the steps of:
introducing the sample undiluted in a microcuvette having at least one cavity for receiving the sample, said cavity being internally pretreated with the reagent in dry form and said chemical reaction then taking place in said cavity, selecting as active components included in the rea-gent at least a hemolysing agent for exposing glucose contained in the blood cells of the sample for allowing a quantitative total glucose determination in a whole blood hemolysate, and agents participating in the chemical reac-tion and ensuring that the dye concentration change takes place at least in a wavelength range outside the absorp-tion range of the blood hemoglobin, and performing an absorption measurement at said wave-length range directly on the sample in the cuvette.
2. Method as claimed in claim 1, character-ised in that a glucose dehydrogenase method is used for the chemical reaction.
3. Method as claimed in claim 2, character-ised in that diaphorase is also selected as active component included in the reagent.
4. Method as claimed in any one of claims 1-3, characterised in that mutarotase is also selected as active component included in the reagent.
5. Method as claimed in any one of claims 1-4, characterised in that, in addition to said absorption measurement in said wavelength range in which said dye concentration change occurs, a secondary absorp-tion measurement is also carried out at a higher wave-length range for providing compensation for background interference.
6. Method as claimed in claim 5, character-ised in that the first-mentioned wavelength range, in which said dye concentration change occurs, is above 650 nm and that said secondary wavelength range in which said compensation measurement takes place, is above 700 nm, preferably 740-940 nm.
7. Method as claimed in any one of claims 1-6, characterised in that said chemical reaction is an end-point reaction, said absorption measurement be-ing carried out only when said dye concentration change is substantially terminated.
8. Disposable cuvette (58) for use in carrying out glucose content determination in whole blood where a sample of whole blood is contacted with a reagent Which by chemical reaction with glucose in the sample brings about a dye concentration change which is detectable in the sample and the size of which is determined as a measure of the glucose content, character-ised in that the cuvette (58) has at least one cavity (60) for receiving the sample, said cavity being internal-ly pretreated with the reagent in dry form and said chemi-cal reaction being intended to take place in said cavity after introduction of the sample in undiluted form, that active components included in the reagent of the cuvette comprise at least one hemolysing agent for exposing glucose contained in the blood cells of the sample for allowing total glucose determination, and agents partici-pating in the chemical reaction and ensuring that the dye concentration change takes place at least in a wavelength range outside the absorption range of the blood hemoglobin, and that the cuvette is at least partly trans-parent for permitting an absorption measurement directly on the sample in the cavity of the cuvette in said wave-length range.
9. Photometer for use in carrying out glucose content determination in whole blood where a sample of whole blood is contacted with a reagent which by chemical reaction with glucose in the sample brings about a dye concentration change which is detectable in the sample and the size of which is determined as a measure of the glucose content, characterised in that the photometer is adapted to be used in combination with an at least partly transparent disposable microcuvette (58) which initially is pretreated with the reagent in dry form and in which the chemical reaction is intended to take place after introduction of the sample in undiluted form in the cuvette, and that the photometer for carrying out an absorption measurement directly on the sample in the cuvette comprises a first light emitting diode (52) having a light wavelength in said wavelength range in which said dye concentration change occurs, a second light emitting diode (64) having a light wavelength separate from said wavelength range, a light detector (40) which during measurement receives light transmitted through the cuvette and the sample, alternately from said first and said second light emitting diode, electronic evaluation means (18, 20, 22, 24; 46) calculating, on the basis of the amount of light measured by the light detector (40), the glucose content of the sample from a difference between the transmittance at the light wavelength of said first light emitting diode (52) and the transmittance at the light wavelength of said second light emitting diode (64), and display means (26, 28) for displaying the glucose content calculated by said evaluation means.
10. Photometer as claimed in claim 9, charac-terised in that the light wavelength of said first light emitting diode (52) is above 650 nm and that the light wavelength of said second light emitting diode (64) is above 700 nm.
11. Photometer as claimed in claim 9 or 10, cha-racterised in that the light from at least one (58) of said light emitting diodes is caused to pass through a monochromatic filter (54).
12. Photometer as claimed in claim 10, characterised in that the light wavelength of the second light emitting diode (64) is within the range of 740-940 nm.
CA002053284A 1989-04-25 1990-04-24 Method for determination of glucose in whole blood and cuvette and photometer for carrying out said method Expired - Lifetime CA2053284C (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
SE8901514-3 1989-04-25
SE8901514A SE466157B (en) 1989-04-25 1989-04-25 DETERMINED TO DETERMINE THE GLUCOSE CONTENT OF WHOLE BLOOD AND DISPOSABLE BEFORE THIS
PCT/SE1990/000273 WO1990012890A1 (en) 1989-04-25 1990-04-24 Method for determination of glucose in whole blood and cuvette and photometer for carrying out said method

Publications (2)

Publication Number Publication Date
CA2053284A1 CA2053284A1 (en) 1990-10-26
CA2053284C true CA2053284C (en) 2001-12-11

Family

ID=20375801

Family Applications (1)

Application Number Title Priority Date Filing Date
CA002053284A Expired - Lifetime CA2053284C (en) 1989-04-25 1990-04-24 Method for determination of glucose in whole blood and cuvette and photometer for carrying out said method

Country Status (18)

Country Link
US (1) US5866349A (en)
EP (1) EP0469097B1 (en)
JP (1) JPH0734758B2 (en)
KR (1) KR960004040B1 (en)
AT (1) ATE133453T1 (en)
AU (1) AU632569B2 (en)
BR (1) BR9007340A (en)
CA (1) CA2053284C (en)
DE (1) DE69025058T2 (en)
DK (1) DK0469097T3 (en)
ES (1) ES2081987T3 (en)
FI (1) FI102192B1 (en)
LT (1) LT3187B (en)
LV (1) LV10121B (en)
NO (1) NO300854B1 (en)
RU (1) RU2050545C1 (en)
SE (1) SE466157B (en)
WO (1) WO1990012890A1 (en)

Families Citing this family (50)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4935346A (en) 1986-08-13 1990-06-19 Lifescan, Inc. Minimum procedure system for the determination of analytes
SE520341C2 (en) 1998-01-14 2003-06-24 Hemocue Ab Method and procedure for mixing in a thin liquid state
US6458326B1 (en) 1999-11-24 2002-10-01 Home Diagnostics, Inc. Protective test strip platform
RU2157994C1 (en) * 1999-12-30 2000-10-20 Институт молекулярной биологии им. В.А. Энгельгардта РАН Method and device for carrying out clinical and biochemical analysis of biological fluids
US6485923B1 (en) 2000-02-02 2002-11-26 Lifescan, Inc. Reagent test strip for analyte determination having hemolyzing agent
SE518539C2 (en) * 2000-06-28 2002-10-22 Migrata U K Ltd Method and cuvette for quantitative hemoglobin determination in undiluted whole blood
US6525330B2 (en) 2001-02-28 2003-02-25 Home Diagnostics, Inc. Method of strip insertion detection
US6541266B2 (en) 2001-02-28 2003-04-01 Home Diagnostics, Inc. Method for determining concentration of an analyte in a test strip
US6562625B2 (en) * 2001-02-28 2003-05-13 Home Diagnostics, Inc. Distinguishing test types through spectral analysis
US6586195B1 (en) 2001-11-19 2003-07-01 R.E. Davis Chemical Corporation Method of detecting sugars
SE0104443D0 (en) * 2001-12-28 2001-12-28 Hemocue Ab Analysis method and cuvette for that
EP1936356A1 (en) * 2002-10-29 2008-06-25 Bayer HealthCare LLC Diffuse reflectance readhead
CA2446368C (en) * 2002-10-29 2014-10-14 Bayer Healthcare Llc Diffuse reflectance readhead
US6900058B2 (en) * 2003-03-11 2005-05-31 Bionostics, Inc. Control solution for photometric analysis
AU2005213658A1 (en) * 2004-02-06 2005-08-25 Bayer Healthcare Llc Fluid testing sensor having vents for directing fluid flow
JP4128160B2 (en) 2004-06-30 2008-07-30 三洋電機株式会社 Control method of mixing ratio detector
BRPI0518638A2 (en) 2004-12-13 2008-12-02 Bayer Healthcare Llc Method of differentiating blood from control solutions containing a common analyte
RU2400733C2 (en) * 2004-12-13 2010-09-27 Байер Хелткэр Ллк Transmission spectroscopy system for use in determining analysed substances in body fluids
US20060281187A1 (en) 2005-06-13 2006-12-14 Rosedale Medical, Inc. Analyte detection devices and methods with hematocrit/volume correction and feedback control
EP2989981B8 (en) 2005-09-30 2018-09-05 Intuity Medical, Inc. Multi-site body fluid sampling and analysis cartridge
SE531041C2 (en) * 2006-07-17 2008-11-25 Hemocue Ab Platelet count
US7797987B2 (en) * 2006-10-11 2010-09-21 Bayer Healthcare Llc Test sensor with a side vent and method of making the same
WO2008057479A2 (en) * 2006-11-07 2008-05-15 Bayer Healthcare Llc Method of making an auto-calibrating test sensor
EP2101634A1 (en) * 2006-12-13 2009-09-23 Bayer Healthcare, LLC Biosensor with coded information and method for manufacturing the same
US20080248581A1 (en) 2007-04-06 2008-10-09 Bayer Healthcare Llc Method for performing correction of blood glucose assay bias using blood hemoglobin concentration
JP2010536035A (en) * 2007-08-06 2010-11-25 バイエル・ヘルスケア・エルエルシー System and method for automatic calibration
WO2009050177A1 (en) * 2007-10-15 2009-04-23 Ima Life S.R.L. Inline measurement of moving containers with infrared (ir) spectroscopy
US8241488B2 (en) 2007-11-06 2012-08-14 Bayer Healthcare Llc Auto-calibrating test sensors
DE102008006245A1 (en) * 2008-01-25 2009-07-30 Nirlus Engineering Ag Method for the noninvasive, optical determination of the temperature of a medium
US20090205399A1 (en) * 2008-02-15 2009-08-20 Bayer Healthcare, Llc Auto-calibrating test sensors
JP2011516118A (en) 2008-03-25 2011-05-26 ザ・キュレイターズ・オブ・ザ・ユニバーシティ・オブ・ミズーリ Method and system for non-invasively detecting blood glucose using spectral data of one or more components other than glucose
EP3556290A1 (en) 2008-05-22 2019-10-23 St. Louis Medical Devices, Inc. Method and system for non-invasive optical blood glucose detection utilizing spectral data analysis
WO2009145920A1 (en) 2008-05-30 2009-12-03 Intuity Medical, Inc. Body fluid sampling device -- sampling site interface
US9636051B2 (en) 2008-06-06 2017-05-02 Intuity Medical, Inc. Detection meter and mode of operation
EP2169384B1 (en) * 2008-09-30 2013-04-10 General Electric Company IR gas sensor with simplified beam splitter.
US8424763B2 (en) * 2008-10-07 2013-04-23 Bayer Healthcare Llc Method of forming an auto-calibration circuit or label
EP2344863A2 (en) 2008-10-21 2011-07-20 Bayer HealthCare LLC Optical auto-calibration method
ES2535289T3 (en) 2008-12-18 2015-05-08 Bayer Healthcare Llc Set to determine the temperature of a test sensor
WO2011065981A1 (en) 2009-11-30 2011-06-03 Intuity Medical, Inc. Calibration material delivery devices and methods
KR101929057B1 (en) * 2010-03-22 2018-12-13 바이엘 헬쓰케어 엘엘씨 Residual compensation for a biosensor
EP2739970B1 (en) 2011-08-03 2016-06-08 Intuity Medical, Inc. Devices for body fluid sampling and analysis
RU2509297C1 (en) * 2012-08-31 2014-03-10 Закрытое акционерное общество Научно-производственное предприятие "ТЕХНОМЕДИКА" Photometric analyser with cell for installation of optic filling cuvet
DE102012018015B3 (en) * 2012-09-06 2013-12-05 Jenoptik Polymer Systems Gmbh Measuring module for remission photometric analysis and method for its production
FR3038723B1 (en) 2015-07-07 2019-06-14 Commissariat A L'energie Atomique Et Aux Energies Alternatives METHOD OF ESTIMATING A QUANTITY OF ANALYTE IN A LIQUID
EP3428623B1 (en) 2016-03-08 2021-06-16 Terumo Kabushiki Kaisha Component measurement device, component measurement method, and component measurement program
FR3049062B1 (en) 2016-03-17 2023-06-02 Commissariat Energie Atomique METHOD FOR CHARACTERIZING A LIQUID SAMPLE COMPRISING PARTICLES
US20190346364A1 (en) * 2016-11-18 2019-11-14 Siemens Healthcare Diagnostics Inc. Multiple sequential wavelength measurement of a liquid assay
WO2018173609A1 (en) 2017-03-23 2018-09-27 テルモ株式会社 Component measurement device and component measurement device set
CN110609002A (en) * 2018-12-29 2019-12-24 深圳迈瑞生物医疗电子股份有限公司 Interference detection method and sample analyzer
CN110715923A (en) * 2019-11-24 2020-01-21 天津市宝坻区人民医院 alpha-D-glucose detection kit

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2964974A (en) 1957-12-24 1960-12-20 Cemam Conord Sa Transmission means for clothes washing machines
US3642444A (en) * 1969-05-02 1972-02-15 Minnesota Mining & Mfg Analytical reagent and method for carbohydrate analysis in body fluids
US3615228A (en) * 1969-11-20 1971-10-26 Dow Chemical Co Glucose determination method employing orthotoluidine
CS164231B2 (en) * 1972-09-28 1975-11-07
SE399768B (en) * 1975-09-29 1978-02-27 Lilja Jan E CYVETT FOR SAMPLING, MIXING OF, THE SAMPLE WITH A REAGENTS AND DIRECT PERFORMANCE OF, SPECIAL OPTICAL, ANALYSIS OF THE SAMPLE MIXED WITH THE REAGENTS
SE422115B (en) * 1976-09-13 1982-02-15 Jan Evert Lilja KYVETT ACCORDING TO PATENT REQUIREMENT 1 OF PATENT 7510863-9
US4120755A (en) * 1977-04-28 1978-10-17 Beckman Instruments, Inc. Kinetic method for determination of glucose concentrations with glucose dehydrogenase
DE7801673U1 (en) 1978-01-20 1979-06-28 Siemens Ag, 1000 Berlin Und 8000 Muenchen ROENTGE DIAGNOSTIC GENERATOR
DE3303098A1 (en) * 1983-01-31 1984-08-02 Boehringer Mannheim Gmbh, 6800 Mannheim METHOD AND REAGENT FOR DETERMINING GLUCOSE IN HAEMOLYSED BLOOD
GB2138936B (en) * 1983-04-26 1986-09-10 Gen Electric Co Plc Optical sensor systems
US4637978A (en) * 1983-10-28 1987-01-20 Eastman Kodak Company Assay for analysis of whole blood
US5112490A (en) * 1986-02-19 1992-05-12 Jon Turpen Sample filtration, separation and dispensing device
US4865813A (en) * 1986-07-07 1989-09-12 Leon Luis P Disposable analytical device
JPS6371653A (en) * 1986-09-16 1988-04-01 Fuji Photo Film Co Ltd Whole blood diluting liquid
JPH0726960B2 (en) * 1988-04-05 1995-03-29 富士写真フイルム株式会社 Dry whole blood analysis element

Also Published As

Publication number Publication date
EP0469097A1 (en) 1992-02-05
JPH0734758B2 (en) 1995-04-19
NO914182D0 (en) 1991-10-24
AU632569B2 (en) 1993-01-07
EP0469097B1 (en) 1996-01-24
LTIP276A (en) 1994-10-25
NO300854B1 (en) 1997-08-04
NO914182L (en) 1991-10-24
FI915021A0 (en) 1991-10-24
ES2081987T3 (en) 1996-03-16
LV10121A (en) 1994-05-10
DK0469097T3 (en) 1996-02-19
RU2050545C1 (en) 1995-12-20
SE8901514D0 (en) 1989-04-25
US5866349A (en) 1999-02-02
LT3187B (en) 1995-03-27
DE69025058D1 (en) 1996-03-07
JPH04504662A (en) 1992-08-20
LV10121B (en) 1995-02-20
BR9007340A (en) 1992-04-21
WO1990012890A1 (en) 1990-11-01
FI102192B (en) 1998-10-30
CA2053284A1 (en) 1990-10-26
DE69025058T2 (en) 1996-05-30
SE466157B (en) 1992-01-07
SE8901514L (en) 1990-10-26
KR920701475A (en) 1992-08-11
ATE133453T1 (en) 1996-02-15
AU5557690A (en) 1990-11-16
KR960004040B1 (en) 1996-03-25
FI102192B1 (en) 1998-10-30

Similar Documents

Publication Publication Date Title
CA2053284C (en) Method for determination of glucose in whole blood and cuvette and photometer for carrying out said method
US6285454B1 (en) Optics alignment and calibration system
US5772606A (en) Method of and apparatus for measuring uric components
US6525330B2 (en) Method of strip insertion detection
Doumas et al. Measurement of direct bilirubin by use of bilirubin oxidase.
WO1996013707A9 (en) Apparatus and method for determining substances contained in a body fluid
EP0816849A2 (en) Method for the determination of analytes
WO1996013707A2 (en) Apparatus and method for determining substances contained in a body fluid
WO1999012021A1 (en) Analyte detection systems
US8068217B2 (en) Apparatus for testing component concentration of a test sample
US5593894A (en) Direct cholesterol assay
WO1998039634A1 (en) Method and apparatus for measurement of blood substitutes
US5252488A (en) Circular dichroism and spectrophotometric absorption detection methods and apparatus
JPS584918B2 (en) Method for measuring glutamate-oxaloacetate-transaminase and glutamate-pyruvate-transaminase
JPH0666808A (en) Chromogen measurement method
CN101071105A (en) Method for determining glucose and 1,5-anhydroglucitol in identicial colorimetric cell
Liu et al. Improved quantitative Apt test for detecting fetal hemoglobin in bloody stools of newborns
EP0707711B1 (en) Direct cholesterol assay
JPH0943242A (en) Method for measuring concentration of glucose
JPH03100444A (en) Device and method for automatic analysis for clinical examination
Artiss et al. Spectral study of bichromatics: Biuret-protein and glucose-hexokinase reactions as visible-ultraviolet models for turbidity
JPS6119933B2 (en)
EP0071650A1 (en) Apparatus for measuring concentration of bilirubin
LoSicco Characterization of a potassium-selective optode membrane implemented using reflectance-mode spectroscopy
Støa Determination of thiocyanate in blood serum

Legal Events

Date Code Title Description
EEER Examination request
MKLA Lapsed
MKEC Expiry (correction)

Effective date: 20121202