JP2545250B2 - Dry analytical material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a dry analytical material for analyzing components contained in a liquid, in particular, a body fluid represented by urine, blood, cerebrospinal fluid and the like.

[Prior Art] An immersion / reading type test piece has been developed for the purpose of quickly and simply testing the components in a liquid. This test piece is made by supporting an analytical reagent component on an absorbent carrier such as paper, and basically, it can be analyzed only by bringing it into contact with a liquid sample in use.

As one of the application examples of such a test piece, for example, it is possible to analyze a liquid sample containing a large amount of solid content such as whole blood by covering the surface of the test piece with a special film as in US Patent No. 3092465. What you have done is known. When whole blood is used as a sample, it is an essential condition for highly accurate measurement to remove the interference caused by a colored substance represented by red blood cells or a chemically active substance. Since the special membrane in the U.S. patent functions to physically remove red blood cells and the like, it is possible to measure low molecular weight substances such as uric acid, urea nitrogen, and creatinine in addition to glucose by using this membrane. .

As a test piece that can use whole blood as a sample, in addition to the above-mentioned U.S. Patents, Japanese Patent Publications Nos.
And so-called multi-layer analytical elements like 57-66359 and the like are also known. These multilayer analysis elements have a structure in which a detection layer, a shielding layer, a spreading layer, etc. are laminated on a liquid impermeable support, and red blood cells, etc. in the spreading layer made of a porous medium, a hydrophilic fabric, a fibrous substance, etc. Interfering substances are trapped.

[Problems of Prior Art] Since the membrane in the above-mentioned US patent is semipermeable,
The polymer substance is also captured together with the solid component. Therefore, it is difficult to measure a polymer substance by applying the technique disclosed in the patent.

On the other hand, in the multi-layer analysis element, prevention of clogging of the developed layer due to solid substances such as blood cell components and macromolecules such as protein components is the greatest problem. As a measure to prevent clogging, use of a three-dimensional lattice structure of organic polymer particles (Japanese Patent Laid-Open No. 55-9085)
9) and the use of a core-shell multi-layer particle structure composed of a core of an inorganic substance and a hydrophilic outer shell (Japanese Patent Laid-Open No. 58-123458) is known, but the manufacturing process of the structure is complicated and There is a problem that it is difficult to secure the void volume.

The multilayer analysis element is generally produced by stacking each layer on a liquid-impermeable support using a hydrophilic binder for the purpose of ensuring mechanical strength. However, since the support used is an originally hydrophobic material such as polyethylene terephthalate, polycarbonate, or polystyrene, it cannot be combined with the hydrophilic binder unless it is rendered hydrophilic by some means.
Therefore, the production becomes more complicated due to the addition of the step of hydrophilizing the support.

[Object of the Invention] An object of the present invention is to provide a dry analytical material which is less likely to be clogged with solid components, macromolecules, etc., can be rapidly tested, and can be produced by a simple method. .

[Structure of the Invention] The present invention provides a dry analysis material in which a reagent component for measuring or detecting a component in a liquid is supported on a non-fibrous porous carrier, wherein the non-fibrous porous carrier has a small pore size. A dry analytical material having a highly asymmetrical shape having a flat surface with a hole and a flat surface with an opening having a large hole diameter, and both openings being in communication with each other.

In the present invention, the non-fibrous porous carrier has a flat surface (hereinafter referred to as a dense surface) having a small pore diameter and a flat surface (hereinafter referred to as a rough surface) having a large pore diameter. It has a highly asymmetrical shape and has both openings communicating with each other. Such a non-fibrous porous carrier is made of a material such as polysulfone, polyamide, polyimide, polycarbonate, polystyrene, or polyaryl hydrazide (JP-A-56-1540).
51) is suitable. In particular, the series of BTS (trade name) filters sold by Brunswick International, Inc. have an average pore size of 0.1 to 0.4 on the dense surface.
It is a polysulfone porous body having a very high degree of asymmetry of 5 μm and an average opening diameter on a rough surface of 10 to 20 μm, and is a suitable material for the dry analytical material according to the present invention.

The open pore size in the dense surface of the non-fibrous porous carrier in the present invention also determines the size of the interfering substance to be captured in the target liquid sample, the physical properties such as the viscosity of the medium, and the molecular weight of the substance to be analyzed. However, generally 0.01-10
It is selected from the range of μm. Further, the ratio of the average pore diameter of the open surface portion of the dense surface and the rough surface is set in consideration of various conditions like the open hole diameter in the dense surface, but generally 1:10.
It is selected from the range of up to 1: 1000. The change in pore size in the non-fibrous porous carrier may be continuous or stepwise.

Here, assuming a dry analytical material using whole blood as a sample as an example of the present invention, setting each parameter of the non-fibrous porous carrier is as follows. That is, the upper limit of the pore size on the dense surface is about 5 μm for complete capture of blood cells,
The lower limit is preferably about 0.1 μm. Further, the ratio of the average pore diameter is preferably about 1:20 to 1: 200 in consideration of the viscosity of serum as a medium.

As the reagent component in the present invention, the same one as the reagent system conventionally applied to various types of test pieces can be used.

The dry analytical material according to the present invention can be obtained, for example, as follows. That is, it is prepared by impregnating or coating a non-fibrous porous carrier in which a reagent component is dissolved or dispersed in an appropriate solvent and then dried. At this time, in order to solve problems such as stability and solubility of the reagent component, the impregnation step may be performed in two or more steps, or different reagent components may be applied to both the dense surface and the rough surface. The solvent used is selected so as not to deform or collapse the structure of the non-fibrous porous carrier. For example, when polysulfone is used as the non-fibrous porous carrier, water, methanol, ethanol, acetone, butyl cellosolve, hexane, etc. may be used.

The analysis using the dry analytical material according to the present invention is performed as follows, for example. That is, a small amount of liquid sample is spotted on either the dense surface or the rough surface of the dry analytical material, allowed to stand for a certain period of time and allowed to diffuse, and then the color tone appearing on the opposite side of the liquid sample spotted surface is observed. Done by. At this time, when whole blood is used as a sample, stronger coloring can be obtained by using the rough surface side as the spotting surface. The color tone can be observed by a method using a mechanical means such as a reflection photometry method, or by a method of visually comparing with a standard color tone table prepared in advance.

[Operation of the Invention] In the present invention, the non-fibrous porous carrier is a carrier for the reagent component, and also has the function of effectively capturing the interfering substance through the communicating holes of the specific condition existing therein. Two
By providing the opening portions with different pore diameters on the two planes, it is possible to simultaneously realize good penetrability in which clogging does not easily occur and reliable capture of interfering substances.

The dry analytical material of the present invention will be described in more detail based on the following examples.

[Examples] Example 1. Glucose analysis material Non-fibrous porous carrier made of polysulfone having an average pore diameter of about 0.1 µm at the open side of the dense surface, a pore diameter of about 10 to 20 µm at the open side of the rough surface, and a thickness of 125 µm [ Brunswick International Co., BTSD100 (trade name)] was impregnated with the following solution and vacuum dried. The obtained reagent-supported non-fibrous porous carrier
A glucose analysis material was obtained by cutting into a square of 10 × 10 mm.

* Impregnation solution Glucose oxidase 9000 U Peroxidase 2500 U 4-aminoantipyrine 0.3 g N-ethyl-N- (2-hydroxy-3-sulfopropyl) -m-toluidine sodium salt 1.45 g 0.5 M citrate buffer (pH 6. 0) 25 ml polyvinylpyrrolidone 1 g mixed with purified water 23 ml ○ Measurement Example Using the glucose analysis material obtained in Example 1, the glucose concentration in whole blood was actually measured. 10 as liquid sample
Using human whole blood containing glucose of 9, 208, 421, and 813 mg / dl, 5 μl of whole blood was spotted on the rough side of the analytical material.
The analysis was performed by measuring the color tone appearing on the dense surface side after a minute by measuring the reflected light at 700 nm. The glucose concentration of each sample was measured by a glucose analyzer (yellow
It was measured by Model 23A manufactured by Spring Instruments. The results are as shown in FIG.

Example 2. Cholesterol analysis material Non-fibrous porous carrier made of polysulfone having an average pore diameter of about 0.45 [mu] m in a dense surface, a pore diameter of about 10 to 20 [mu] m in a rough surface, and a thickness of 125 [m] [Brunswick International Co., Ltd. Manufactured by BTSD450 (trade name)] was impregnated with the following solution and vacuum dried. The obtained reagent-supported non-fibrous porous carrier
Cholesterol analysis material (hereinafter referred to as the product of the present invention) was obtained by cutting into 10 × 10 mm squares.

* Impregnation solution Cholesterol oxidase 500 U Cholesterol esterase 4500 U Peroxidase 460 U 0.5% Triton X-100 3 ml 0.5 M Phosphate buffer (pH 7.0) 2 ml 4-Aminoantipyrine 33 mg N-Ethyl-N- (2 -Hydroxy-3-sulfopropyl) -3,5-dimethoxyaniline sodium salt 90 mg was mixed. Comparative Example The non-fibrous porous carrier of Example 2 was replaced with a pore size of about 0.45 μm and a dense surface. By using a symmetrical cellulose mixed ester membrane filter [HAWP (trade name) manufactured by Japan Millipo Limited, Inc.) that does not have a rough surface and a rough surface, a cholesterol analysis material for test (hereinafter referred to as a comparative product) is obtained by the same operation. Got

5 μl of human whole blood having various cholesterol concentrations was spotted on the rough surface of the product of the present invention and one surface of the comparative product to compare the performance. As a result, in the product of the present invention, blood was diffused / permeated on the circle 30 seconds after the spotting, and after 1 minute, a bluish purple color having an intensity corresponding to the cholesterol concentration was observed on the dense surface side. On the other hand, in the comparative product, the blood was not completely absorbed even after 5 minutes from the spotting, and the blood on the opposite side was colored by the blood cell component after 5 to 10 seconds, and the bluish purple coloration due to cholesterol was observed. It was extremely difficult to do.

[Effects of the Invention] As is clear from the examples, the dry analytical material according to the present invention can be prepared by a much simpler operation than that of the multilayer analytical element.

Further, according to the dry analytical material of the present invention, as is clear from the measurement example, highly accurate measurement can be performed using whole blood or the like as a sample.

Further, the dry analytical material of the present invention showed a clear improvement in clogging, as is clear from the comparative examples.

As described above, the dry analytical material according to the present invention is extremely useful particularly in the analysis of components in a liquid using a sample such as whole blood.

[Brief description of drawings]

FIG. 1 is a graph showing the analysis results of glucose-containing blood obtained using the glucose analysis material according to the present invention. The vertical axis represents the reflection optical density, and the horizontal axis represents the glucose concentration in blood.

Claims (3)

(57) [Claims] 1. A dry analytical material in which a reagent component for measuring or detecting a component in a liquid is supported on a non-fibrous porous carrier, wherein the non-fibrous porous carrier has an opening portion having a small pore diameter. Dry analytical material characterized by a highly asymmetrical shape having a flat surface and a flat surface with a large pore size opening, and wherein both openings are in communication 2. The dry analytical material according to claim 1, wherein the ratio of the average pore diameters of the small openings and the large openings is 1:10 to 1: 1000. 3. The dry analytical material according to claim 1, wherein whole blood is used as a sample for analysis.