JPH01107136A - Liquid analysis - Google Patents

Abstract

PURPOSE:To enable clinical chemical analysis with high accuracy by a method wherein, a standard liquid of different concentration is drip-deposited on at least two units of the same dry analysis element, permitting the collection of a sample even from a patient at home, for example. CONSTITUTION:When a specific component in liquid is to be analyzed using a dry analysis element, a sample is drip-deposited on a unit of said element by which the component is detected by its optical variation. At the same time the standard liquid is applied on at least another unit on the same dry analysis element. After preservation under the same conditions, optical variation on the element is measured. Therefore, analysis which permits the identification of the concentration of a specific component in a sample enables highly accurate clinical chemical analysis.

Description

[Detailed Description of the Invention] [Prior Art and Its Disadvantages] Dry analytical elements, like so-called test strips and clinical chemistry analysis slides, contain all the reagents necessary for the detection of specific components in a dry state, and When brought into contact with this, a reaction with the reagents occurs, and by measuring the resulting optical and electrical changes, the specific component can be detected quantitatively or semi-quantitatively.

Conventionally, when the purpose is quantitative analysis, a specimen is spotted on an analytical element, incubated under certain conditions (for example, 37°C for 5 minutes) to cause a reaction, and then optical measurements etc. are performed to determine the specimen. It was common practice to calculate the concentration of specific components inside.

Recently, devices have been commercially available that automatically perform the steps after incubation, and can provide satisfactory reproducibility and accuracy. However, many of these devices require (1) a power source;

(2) It has a certain size.

(3) Because it is complex, precise, and expensive, etc.
They cannot be installed everywhere, so the installation of such devices is limited to hospitals or large clinics.

For example, if a diabetic outpatient at a hospital were to measure their blood sugar levels several times in their daily lives and bring the results with them when they visit the hospital, the treating doctor would be able to more accurately understand the patient's condition. .

There are devices that can be used for semi-quantitative measurements at home, but their accuracy is low and they are not suitable for the above purpose.

Another method is to place a specimen collected by the patient in daily life on an analytical element (element) and bring the analytical element to the hospital for measurement, but the Due to fluctuations in external conditions, changes in specimens and analysis elements, the accuracy is significantly reduced and is not useful for basolateral diagnosis.

Therefore, samples are collected during the patient's daily life at home etc.
Moreover, it is extremely desirable to be able to perform clinical chemical analysis with analytical accuracy that is not much different from that obtained when testing is performed using an automatic analyzer in a hospital or the like.

[Technical Problems to be Solved] The present invention makes it possible to collect a patient's specimen outside of a hospital where an automatic analyzer is installed, for example at home, and to collect the analytical elements at the place where the automatic analyzer is installed. The technical challenge is to enable clinical chemistry analysis with the same analytical accuracy as spot testing.

[Means for solving the technical problem] The above problem is solved by spotting a sample on one unit of the dry analysis element that detects the specific component by a sudden optical change when analyzing a specific component in a liquid using a dry analysis element. At the same time, a standard solution is spotted on at least one other unit of the same type of dry analytical element, and after storing those dry analytical elements under the same conditions, measuring the optical change that occurs in the dry analytical element, This problem was solved by an analytical method that determines the concentration of specific components in a sample.

[Specific Structure of the Invention] The object of the present invention can be more preferably achieved by applying reference solutions of different concentrations to at least two units of the same type of dry analysis element. ? The more the degree level is increased, the easier it becomes to improve the analysis accuracy. However, in terms of the cost and effort required for analysis, it is better to have a lower concentration level.
Choose appropriately.

Dry analytical elements have at least one liquid-permeable porous layer. This layer may contain all or part of the reagent that reacts with the component to be detected. A portion of the reagent may be contained in layers at different depths of one porous layer. A separate non-porous, liquid-permeable layer may also contain some or all of the reagents described above. It may have two or more porous or non-porous liquid permeable layers.

Dry analytical elements may have a light-transmissive or transparent support, which may be liquid-permeable, such as paper, or liquid-impermeable, such as plastic.

Dry analytical elements are disclosed in U.S. Pat. No. 3,992,158 and U.S. Pat.
, 292, 272, in which a liquid-permeable layer containing at least a portion of a reagent and a further porous layer are successively provided on a transparent, water-impermeable support. Preferably, it is an element.

The integrated multilayer analytical element is also described in U.S. Patent No. 3,983,005.
, 4,042,335, 4,066.403, 4
, 144,306, 4,132,528, 4,25
8,001, 4.357.363, 4,381,4
It may have a configuration as described in No. 21 or the like.

It may have a plurality of porous layers as described in JP-A-61-4959, JP-A-62-138756, JP-A-62-138757, and JP-A-62-138758.

Even if the integrated multilayer analytical element is used in a format that detects optical changes near the substantial end point of the reaction between a specific component in a sample and a reagent in the analytical element, the reaction rate cannot be determined from the rate of color development during the reaction. It may also be used in a measuring format. However, since a considerable amount of time elapses from sample collection to optical measurement, a method that utilizes the end point of the reaction is more suitable.

Analytical elements that can be applied to the present invention can be measured colorimetrically, regardless of detection component, type of reaction, composition, measurement wavelength, etc. However, in extreme cases where the color completely disappears during storage, this Unsuitable for invention.

The present invention can also be applied to analytical elements made for analysis by rate assay, as long as the optical density when applied and left to stand corresponds to the concentration of the analyte.

The preservation of analytical elements in the present invention differs from the case where the analytical elements are incubated under certain conditions in a colorimetric measuring device after spotting the sample solution, and then optically measured after a certain time or at fixed time intervals, from spotting to measurement. The storage time does not have to be strictly constant; the storage period varies considerably depending on the case, and ranges from several tens of minutes to several tens of days. Of course, a constant temperature chamber or the like may be used to maintain constant storage conditions during all or part of the storage period.

It is preferable that the number of analytical elements on which the standard solution is applied is two or more units.
It is preferable to spot more than one type of standard solution in order to improve analysis accuracy.The same concentration of standard solutions may be spotted on two or more units of analytical elements. By doing so, analysis accuracy can be improved.

The optical change used for detection is not limited to color development, but may include color change (change in absorption wavelength), fluorescence, luminescence, and the like. The reaction utilized may be a reaction involving an enzyme in a specimen or an analytical element, or may be an immunological reaction.

The component to be detected (analyte) may be a low-molecular substance, an ion, or a high-molecular substance, and may be either a hydrophilic substance or a hydrophobic substance.The component to be detected may be an enzyme, an antigen, or a hydrophobic substance. It may also be an antibody. The antigen or antibody may be labeled with an enzyme or a fluorescent substance, or may be bound to another polymer. The antigen may be a hapten.

Examples of analytes: Low molecules: urea, uric acid, ammonia, creatinine, lactic acid, pyruvic acid, glucose, galactose, neutral fat, cholesterol, hemoglobin, bilirubin, Ions: calcium, potassium, sodium, chloride ions, High molecules: protein (albumin, globulin, etc.), nucleic acids, riboproteins, enzymes: amylase, phosphatase, lipase, lactate dehydrogenase, creadine phosphokinase, alanine aminotransferase, asparagine aminotransferase The present invention is useful for diagnosis, treatment progress determination, health management It is useful for quantifying various analytes in body fluids such as blood (whole blood, etc.) and urine. The analysis method of the present invention can be applied to analysis of either diluted or undiluted whole blood.

The analytical element used in the present invention contains at least one type of interaction composition. The interaction composition is an analyte or a reaction product of an analyte or with decomposition products or with each other,
In the analytical elements used in the present invention, which contain one or more interacting active ingredients, dyes that can be detected spectrophotometrically, either directly or indirectly (via other reactions) by such interaction, Fluorescent substances etc. are generated, decomposed or inactivated. Pigments may be produced by interactions between specific components of the blood and chromogenic substances, or by release of diffusible dyes from non-diffusible dyes. chemical activity, catalytic activity, such as in the formation of enzyme-substrate complexes, immunogenic activity, such as in antigen-antibody reactions, and concentration of dyes directly or indirectly indicate the presence or concentration of a particular analyte. Any chemical or physical interaction that can liberate, form or generate a detectable dye such as a dye is included.

The reagent composition contained in the analytical element of the present invention is a composition capable of producing an optically detectable substance, such as a dye, in the presence of a test component. Compositions that produce dyes by oxidation of leuco dyes (see, for example, U.S. Pat. No. 4,089,74
No. 7, JP-A-59-193352, etc., compositions containing arylimidazole leuco dyes), diazonium salts, and compounds that produce dyes by coupling with other compounds when oxidized ( For example, 4-aminoantipyrines and phenols or naphthols),
A compound consisting of a compound capable of producing a pigment in the presence of a reduced coenzyme and an electron transfer agent can be used.

Examples of leuco dyes include U.S. Pat. No. 4,089,747.
Examples include triarylimidazole leuco dyes such as those described in JP-A-59-193352, known triarylmethane leuco dyes, and the like.

Examples of oxidizable compounds in which a dye may be formed by a dye-forming composition containing a condensation product of an oxidizable compound and a color former include benzidine and its congeners, p-phenylene diaminos, p- Examples include amine phenols, aminoantipyrine, such as 4-aminoantipyrine.

In addition, in the case of analytical elements for measuring enzyme activity, for example, p
- A self-developing substrate that can reproduce colored substances such as dil-lophenol (e.g., palani I - lophenyl phosphate, barani I - lophenyl maltopentaose, γ-
glutamyl varanitroanilide) can be included in the reagent layer or the developing layer.

The reagent composition may contain an enzyme, and the eldest daughter's 1-''
Those described on pages 18 to 20 of the specification of JP-A-62-138756 can be used.

The reagent composition may be contained entirely or in part in a substantially uniform layer with a hydrophilic polymer as the binder. Hydrophilic polymers include, for example, gelatin and derivatives thereof (e.g. phthalate), cellulose derivatives (e.g. hydroxypropyl cellulose, carboxymethyl cellulose), agarose, acrylamide polymers, methacrylamide polymers, acrylamide or methacrylamide, and various vinyl polymers. Copolymers with monomers, copolymers with polyvinyl and lolidone, copolymers with polyvinylpyrrolidone and various vinyl monomers, etc. can be used.

A portion or all of the reagent composition may be included in the porous layer. In order to have at least one of the porous layers contain a reagent composition that develops color in the presence of the test component, an appropriate amount of the reagent composition may be included. A method of adhering a porous spreading layer pre-impregnated or coated with a suitable solution or dispersion onto another water-permeable layer, such as a reagent layer, as described in JP-A-55-164356, can be used.

After adhering the porous layer onto other water-permeable layers (e.g., undercoat layer, adhesive layer, water absorption layer) by the method described in JP-A-55-164356, a solution or dispersion of the reagent composition is applied. The liquid may be applied to the porous layer.

Known methods can be used for impregnating or coating the porous layer. For example, dip coating, doctor coating, hopper coating, carden coating, etc. are selected and used as appropriate.

The reagent composition may be contained entirely in one porous layer, for example, in the porous layer closest to the support among two or more porous layers, or it may be contained separately in two or more porous layers. good.

The element may have, for example, a light blocking layer or a vortex layer as described in US Pat. No. 4,042,335.

The liquid interlayer is comprised of any suitable kpi fibrous or non-fibrous material, or mixtures thereof, with suitable porosity and average pore size capable of absorbing whole blood. Preferably, the liquid spreading layer provides a uniform amount of analyte liquid per unit area on the side facing the adjacent water permeable layer with which it is in liquid contact. A useful liquid spreading layer is described in U.S. Pat.
R'l@ya special tmlT'Q described in No. 92,272
[No. 30-222,769] Can be composed of a fibrous material such as a loose knitted fabric. Also, U.S. Pat.
It can also be constructed using an isotropic porous material (for example, a plush polymer) as described in No. 92, 1.58.

When whole blood is used as a sample in the present invention, the analytical element 5 preferably has a layer that filters and removes substantially all or at least a portion of blood cells. The liquid spreading layer may have this function at the same time, and those made of the above-mentioned woven or knitted materials are useful.

In the developing layer, in order to adjust the developing surface area, developing speed, etc.
It may contain a hydrophilic polymer or a surfactant as described in No. 61-122876 and No. 61-143754.

When a light-transmitting support is used, the practically preferred structure of the dry analytical element of the present invention is (1) having a reagent layer on the support and a liquid spreading layer thereon.

(2) A device having a detection layer, a reagent layer, and a liquid development layer in this order on a support.

(3) A support having a reagent layer, a light reflection layer, and a liquid development layer in this order.

(4) A support having a detection layer, a reagent layer, a light reflection layer, and a liquid development layer in this order.

(5) A detection layer, a light reflection layer, a reagent layer, and a liquid development layer are present in this order on a support.

In (1) or (3) above, a water absorption layer may be provided between the support and the reagent layer. In (1) or 3) above, a blood cell filter may be provided between the reagent layer and the detection layer or the liquid development layer. A vortex layer or other vortex layer may be provided. In (3) to 5) above, between the light reflection layer and the detection layer, the reagent layer or the liquid development layer, between the reagent layer and the detection layer, or between the reagent layer and the liquid development layer, further hemocyte filtration M Alternatively, other filter vortex layers may be provided.

The analytical element of the invention may have a light reflective layer.

For example, a light reflecting layer can be provided between the reagent layer and the detection layer or between the reagent layer and the liquid developing layer. The light-reflecting layer is used to measure the detectable changes (color change, color development, etc.) that occur in the detection layer, reagent layer, etc. from the light-transmitting support side. It blocks the color of the liquid, especially the red color of hemoglobin when the sample is whole blood, the yellow color of bilirubin, etc., and functions as a light reflective layer or background layer. The light-reflecting layer is preferably a water-permeable layer in which light-reflecting fine particles such as titanium oxide or barium sulfate are dispersed using a hydrophilic polymer as a binder. The binder may include gelatin, gelatin derivatives, polyacrylamide, etc. preferable.

A hardening agent may be added to hardenable polymers such as gelatin. Analysis elements include a development layer, reagent layer,
The detection layer or the like may contain light-reflective particles such as titanium oxide.

The analytical element of the present invention may have a layer that substantially filters and removes whole blood cells, separate from the liquid spreading layer.

For example, JP-A-58-70163, JP-A-61-495
No. 9, Patent Application No. 60-256408, No. 60-2798
No. 59, No. 60-279860, No. 60-27986
Porous layers such as those described in No. 1 and others are suitable.

One or more layers of the elements of the invention may contain one or more other various optional ingredients, such as surfactants,
It may contain a solvent for a coloring agent, a buffer, a binder, a hardening agent, and the like. These components can be present in amounts known to those skilled in the art. Typical element components are, for example, U.S. Pat. No. 3,992
, No. 158, No. 4,042゜335, No. 4,144,
No. 306, No. 4,132,528, No. 4゜050.8
No. 98, No. 4,258,011, No. 4,275,15
No. 2, No. 4,292,272, etc.

In order to obtain more accurate and precise test results, the element may be incubated (heated) at a certain temperature for a certain period of time before optical measurement.

For spectrophotometric measurements known suitable devices are used, for example U.S. Pat.
, No. 488,810, No. 4,584,275, Japanese Unexamined Patent Publication No. 1983
No. 1-294367, No. 61-294368, No. 62
-184335.

No. 62-184336, Japanese Patent Application No. 31-25582, No. 61-25583, No. 61-40890, No. 6
From No. 1-87708 to No. 87710, No. 01-10
No. 9402-, No. 61-144258, No. 61-18
No. 547'1, No. 61-185472, No. 61-20
7044 to 207049, etc., "Fuji Drikeno, 1000", the same r2000.
, same r 5000 j analyzer (both manufactured by Fuji Photo Film Co., Ltd.), rEkLacbc+a 400
J.

rEktnche+l1700J, rEktae
hem DT-60J analyzer (manufactured by Eastman Kodak Company), etc. can be used.

(Go to next page) Hereinafter, the present invention will be explained in more detail with reference to Examples.

[Example 1] Whole blood 1 and whole blood 2 were prepared by adding a small amount of glucose (powder, manufactured by Wako Pure Chemical Industries, Ltd.) to whole blood collected from a human (heparin was used as an anticoagulant). , 10μ of each was deposited on a Fuji Drychem GLU-WJ slide for whole blood glucose analysis manufactured by Fuji Photo Film Co., Ltd. On the other hand, a control solution for whole blood glucose analysis rGLU-W control manufactured by Fuji Photo Film Co., Ltd. 10 μ each of “liquid” ■ and ■! , spotted on the above analysis slide.

Immediately after spotting, the glucose concentration was measured using a reaction measuring device "Fuji Drychem 2000" manufactured by Fuji Photo Film Co., Ltd., using an analyzer (reaction temperature: 37° C., reaction time: 6 minutes). The results are shown in Table 1.

Table 1 The above value will be referred to as the "true value" hereinafter.

Next, arrange the new analysis slides on the desk, and add 10 μ of control solution to one slide, control solution ■ to one slide, whole blood 1 to the seventh slide, and whole blood 2 to the fifth slide! It was applied and left at room temperature for one day.

These slides were measured using a Fuji Drychem 2000 J Analyzer to determine the glucose concentration.

These are called "r uncorrected values".

Using the true values and uncorrected values of the control solutions ■ and ■ obtained above, the relational expression between the true value and the uncorrected value ° (true value) = aX (
Uncorrected value) + b [Constants a and b for 1 piece were determined.

Next, the formula created using these constants n and b (correction value) = a
X (uncorrected value) + b [The uncorrected values obtained for whole blood 1 and whole blood 2 were substituted into 2 columns to obtain the corrected values. Second result
Shown in the table. In both cases, the deviation from the true value is -l-1eag7
dl, -2rag/d1, which was a good result. The standard deviation SD and coefficient of variation CV are also sufficiently small.

Table 2 [Comparative Example 1] The same operation as in Example 1 was carried out, except that the correction using the control solutions (■) and (■) was omitted, and the uncorrected values of whole blood 1 and whole blood 2 were used as they were. The results are shown in Table 3. SD and C■
were not significantly different from those in Table 2, but the deviations from the true values were -6 vag/dl and -18 mg/dl, respectively, which were one digit larger than in Example 1.

Table 3 Applicant: Fuji Photo Film Co., Ltd.

Claims (3)

[Claims] (1) A method of analyzing a specific component in a liquid using a dry analytical element, in which a sample is spotted on one unit of the dry analytical element that detects the specific component by optical change, and at the same time After spotting the standard solution on at least one other unit of the analytical element and storing the dry analytical elements under the same conditions, the optical change that occurs in the dry analytical element is measured and the concentration of the specific component in the sample is determined. An analytical method characterized by determining. (2) The analysis method according to claim (1), characterized in that reference solutions having different concentrations are spotted on at least two units of dry analysis elements of the same type. (3) The dry analytical element is stored under the same external conditions and kept at a constant temperature for a certain period of time, and then the optical change occurring in the dry analytical element is measured. Analysis method for range (1).