JPH04315947A - Disc-shaped analytical element - Google Patents

Abstract

PURPOSE:To enable specific components in a liquid sample to be accurately analyzed at good reproducibility and at low cost using a small device by forming a porous expanded layer on that surface of a disc on which the liquid sample is dropped. CONSTITUTION:A reagent is applied on a rigid, transparent support and a porous expanded layer is applied thereon to form a disc-shaped analytical element D of diameter about 5 to 25cm. The element D is placed on a turntable and rotated in the direction of the arrow and light is applied from the lower surface of the element D and the light reflected at the element D is measured so as to determine quantities of specific components in a liquid sample dropped on the element D by a dropping means 1. The dropping means 1 is movable in the direction of the radius vector of the element D, and a temperature control means 3 controls the reaction of the specific components of the liquid sample dropped 1 with reagent components contained in the reagent layer of the element D. Such a disc-shaped element D is so large in area that the manufacturing cost is reduced together with troublesome operation and that a number of items of measurements can be carried out simultaneously using one element D.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk-type analytical element for analyzing a specific component in a liquid sample deposited on it.

0002

BACKGROUND OF THE INVENTION Analysis of various metabolic components present in body fluids, such as glucose, pirirubin, uric acid, cholesterol, lactate dehydrogenase, creatininase, GOT, and GPT, is important in clinical medicine. A chemical analysis slide using a dry multilayer film has been developed as a means to quickly analyze such trace components with high precision.

[0003] Various types of chemical analysis slides have been proposed depending on their layered structure. For example, slides made of plastic have an opening in the center of the top surface for dropping a liquid sample such as blood, and an opening for photometry in the center of the bottom surface. A dry multilayer film is housed in a slide frame, and the dry multilayer film is composed of a transparent support, a reagent layer, a reflective layer, a spreading layer, etc. The transparent support is, for example, a thin, primed plastic film. The reagent layer coated on the transparent support contains a reagent that reacts with the test component contained in the liquid sample that is spotted and develops a color with an optical density depending on the amount of the component. The reflective layer prevents the light incident on the reagent layer from reaching the developing layer, and prevents the liquid sample spotted on the developing layer from being photometered. The spreading layer spreads the deposited liquid sample uniformly over an area approximately proportional to the amount of liquid. Then, when a liquid sample is spotted from the spotting opening onto the developing layer of a chemical analysis slide, the liquid sample is developed on the developing layer, passes through the reflective layer, reaches the reagent layer, where it reacts with the reagent, and develops color. Therefore, after a predetermined period of time, light is irradiated onto the reagent layer through a photometric aperture, the reflected light is measured in a specific wavelength range, the reflection concentration is determined, and quantitative analysis is performed based on the calibration curve data determined in advance. There is.

[0004] Although such chemical analysis slides have various advantages, there are problems in terms of cost. Therefore, in order to solve these problems, a tape-type device, which is an elongated version of the slide-type device, has been proposed (Japanese Patent Laid-Open Publication No. 313063/1983).

[0005] However, this tape-type analytical element is usually wound during storage, and therefore, depending on the winding pressure, the spreading layer may be damaged. Moreover, since it is bent, distortion of the developing layer and reagent layer is unavoidable, and damage to the reagent layer and developing layer cannot be avoided. Furthermore, during measurements, tension must be applied to the tape-type analytical element from the tip side to allow it to run, and back tension must be applied from the rear side to ensure that the tape-type analytical element does not sag. Therefore, if the applied force is not precisely controlled, distortion may be caused in the development layer and reagent layer of the tape-type analytical element, which may reduce the accuracy of analysis. . In addition, it is not possible to measure multiple items at the same time, that is, it is not possible to apply liquid samples to the tape-type analytical element in parallel, and therefore it is necessary to improve the measurement workability. Furthermore,
There is also the problem that the device itself becomes larger.

[0006]

DISCLOSURE OF THE INVENTION A first object of the present invention is to provide a technique that enables accurate analysis of specific components in a liquid sample with good reproducibility. A second object of the present invention is to provide a technique that reduces analysis costs.

[0007] A third object of the present invention is to provide a technique that can reduce the size of an analyzer. The object of the present invention is to provide a disk-type analysis element for analyzing specific components in a sample by spotting a liquid sample on a disk, which has a porous spread layer formed on the spotting surface of the liquid sample. This is achieved using a distinctive disk-shaped analytical element. In other words, by using a disk-type analytical element, the drawbacks of the slide type, that is, the cost problem, can be solved in the same way as with the tape type, and the problem that occurs with the tape type, that is, damage to the developing layer and reagent layer, can be solved. , there is no reduction in measurement accuracy due to distortion of the developing layer or reagent layer, and since liquid samples can be deposited in parallel, multiple items can be measured at the same time, the measurement workability is good, and the device itself is more compact. This also makes it possible.

[0008] The shape of the disc may be polygonal, but generally a circular disc is used. Although there are no particular restrictions on the size, the diameter is generally from several cm to several tens of cm. The disk-type analytical element of the present invention has, for example, the following layer structure. (1) One having a liquid spreading layer containing a reagent composition on a support. (2) One having a reagent layer and a liquid developing layer in this order on a support. (3) A device having a detection layer, a reagent layer, and a liquid development layer in this order on a support. (4) One having a reagent layer, a light reflection layer, and a liquid development layer in this order on a support. (5) A support having a detection layer, a reagent layer, a light reflection layer, and a liquid development layer in this order. (6) A support having a detection layer, a light reflection layer, a reagent layer, and a liquid development layer in this order.

[0009] The disk-type analytical element of the present invention has a liquid spreading layer containing a reagent composition, or a reagent layer and a liquid spreading layer laminated on a transparent and liquid-impermeable support. However, examples of the support that can be used in the present invention include polymeric compounds such as cellulose acetate, polyethylene terephthalate, polycarbonate, and polyvinyl compounds (eg, polystyrene), and transparent inorganic compounds such as glass.

The liquid spreading layer for uniformly spreading the deposited liquid sample over an area approximately proportional to the amount of liquid is made of a fibrous or other porous layer, such as pulp, Powder filter paper, cotton, linen, silk, wool, chitin, chitosan, cellulose ester, viscose rayon, copper ammonia rayon, polyamide (6-nylon, 66-
Fibers such as nylon, 610-nylon, etc.), polyesters (polyethylene terephthalate, etc.), polyolefins (polypropylene, vinylon, etc.), glass, asbestos, etc., such as vegetable, animal, mineral, synthetic, semi-synthetic, and recycled fibers are used. Furthermore, these may be used as a mixture. In addition, water-absorbing Western paper, Japanese paper, filter paper, brushed polymer, woven fabric, nonwoven fabric, synthetic paper, etc. made of the above-mentioned fibers alone or in combination can also be used.

[0011] Furthermore, when forming a non-fibrous porous spreading layer, granular particles that do not have self-bonding properties can be formed into a film by point-adhering the particles to each other using an appropriate adhesive.
For example, JP-A-49-53888, JP-A-55-908.
Methods such as those disclosed in Japanese Patent No. 59 and Japanese Patent No. 57-67860 can be applied. Organic polymer particles having self-bonding properties are disclosed in Japanese Patent Application Laid-open No. 57-101760 and Japanese Patent Application Laid-open No. 57-10.
Films can be similarly formed by the methods described in JP-A No. 1761, JP-A No. 58-70163, and the like. Regarding fibers or fiber-particle mixtures, see JP-A-57-125847, JP-A-57-125847;
A porous layer can be formed by applying the fiber dispersion described in Japanese Patent No. 7-197466. Also, JP-A-6
As in the method described in Japanese Patent No. 0-173471, it can be formed by applying a dispersion of fibers and/or granules using a hydrophilic binder such as gelatin, polyvinylpyrrolidone, or polyvinyl alcohol. The hydrophilic binder can be freely applied in the required amount, but it may be 0.1 to 25 wt% based on the weight of the granules and/or fibers;
Preferably, it is used in an amount of 1.0 to 20 wt%.

Examples of typical surfactants that can be used include non-containing surfactants such as Triton There are ionic surfactants and ionic surfactants. These surfactants are used in an amount of 20 wt% to 0.005 wt%, preferably 15 wt% based on the weight of the granules and/or fibers, although there is no particular restriction on the amount used.
It can be used in an amount of wt% to 0.1 wt%. Furthermore, other methods include ultrasonication, physical mixing, and physical agitation of the fibers and particle units with a liquid carrier, and pH adjustment. By combining these with the above methods,
Even more useful.

For example, preservatives, surfactants, mordants, buffers, etc. can be added to the constituent layers of the analytical element of the present invention, depending on the purpose. Preservatives are included to stabilize the storage of the substrate coloring reagent, and include antioxidants and the like. In addition, in order to maintain the stability of the substrate contained in the layer, immobilized enzyme,
affinity chromatography absorbers, immobilized antibodies,
It also contains preservatives used to preserve proteins, enzymes, etc. The substances are listed in "Biochemistry Experiment Account I, Protein Chemistry I" edited by the Japanese Biochemical Society (Tokyo Kagaku Doujin Co., Ltd.)
1976) pp66-67, Experiments and Applications "Affinity Chromatography" pp16-104, JP-A-1986-1
Examples include those described in Japanese Patent No. 49927.

Specific examples include gelatin, gelatin decomposition products, albumin, cyclodextrins, non-reducing sugars (sucrose, trehalose), polyethylene glycol, amino acids, various ions, sodium azide, and the like. A hardening agent can be added to the polymer material layer made of hydrophilic colloids such as gelatin or gelatin derivatives, and as the hardening agent, substances widely used in the photographic industry can be used. H. Edited by James “The
Theory of the Photography
phic Peocess) (4th) pp77-8
7 can be mentioned. Specific examples include aldehydes, active olefins, active esters, and the like.

[0015] Examples of the surfactant include those mentioned above. Other reagents contained in the layer include a solubilizing agent and a blocker reagent. These additives are added in appropriate amounts as necessary. A mordant is a substance that concentrates the detection substance for enzyme activity measurement in the detection layer, increases the absorbance coefficient when the detection substance is a dye, or shifts the wavelength, and has a strong interaction with the detection substance. show. Cationic polymers, anionic polymers and latexes of these polymers are used.

[0016] A buffer is contained to maintain a pH suitable for specific binding reactions, enzymatic reactions, coloring reactions, and the like. Buffers that can be used are described in "Chemical Handbook Basic Edition" edited by the Chemical Society of Japan (Tokyo, Maruzen Co., Ltd., 1966) pp. 1312 to 1320, N. E. Good et al; Biochemi
try (vol 5, p467 (1966)), Imamura, Saito; Chemistry, vol 30 (2), p79
(1976), W. J Ferguson et al., Ana
l. Biochem. , vol 104, p300 (
Examples include those described in documents such as 1980). Specific examples include citrate, borate,
Examples include phosphates, carbonates, trisbarbiturate, glycine, Good's buffer, and the like. These buffering agents may be contained in layers other than the reaction layer and detection layer, if necessary.

The analytical element of the present invention can further be provided with auxiliary layers such as a blood cell separation layer useful when the fluid sample is blood (whole blood), an adhesive layer provided as necessary, a protective layer, and a timing layer. The positions where these layers should be provided are easily determined according to their functions. For example, the above (
In 1), (2), and (4), a water absorption layer may be provided between the support and the liquid developing layer or the reagent layer, and (2) to
In (4), a blood cell filtration layer may be provided between the reagent layer and the detection layer or the development layer, and in (4) to (6), a blood cell filtration layer may be provided between the light reflection layer and the detection layer, the reagent layer, or the development layer. A blood cell filtration layer or an obstruction removal layer may be provided between the reagent layer and the detection layer, or between the reagent layer and the development layer.

The various layers described above can be formed into layers of arbitrary thickness by using slide hopper coating methods, extrusion coating methods, dip coating methods, etc., which are known in the photographic industry.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing the principle of measurement using a disk-type analytical element according to the present invention. In the figure, D is a disc-shaped analytical element with a diameter of 5 to 25 cm, and this analytical element D is coated with a reagent layer on a rigid transparent support, and a porous spreading layer coated thereon in order. It is set up. The analysis element D is placed on a turntable (not shown), and the rotation of the turntable causes the disk-shaped analysis element D to be rotated in the direction of the arrow.

Reference numeral 1 denotes a spotting means consisting of a micropipette or the like, and this spotting means 1 is constructed so as to be movable in the radial direction of the disc-shaped analytical element D. In addition, in this example,
Although only one spotting means 1 is shown, a plurality of spotting means 1 may be provided. 2 is a photometric means, which is a disc-shaped analytical element D.
Light is irradiated from the bottom surface of the liquid sample, and by measuring the reflected light, it is possible to quantify a specific component in the liquid sample spotted by the spotting means 1.

Reference numeral 3 denotes a temperature control means disposed below the disc-shaped analytical element D, which causes a reaction between a specific component in the deposited liquid sample and a reagent component in the reagent layer of the disc-shaped analytical element D. is configured to be controlled. Although not shown, a cover for preventing evaporation of the deposited liquid sample is provided on the upper side of the disc-shaped analytical element D, as necessary, particularly in correspondence with the position of the temperature control means 3. Further, the signal detected by the photometry means 2 is inputted to a predetermined calculation means, and after the calculation, the value is printed out.

[0022] When the disc type analytical element constructed as described above is used, the drawbacks and cost problems of the conventional slide type are solved. In other words, since one disk-shaped analytical element D has a large area, it does not take much time and the manufacturing cost is low.Moreover, it is possible to perform several measurements with one disk-shaped analytical element D, especially at the same time. Measurement is also possible, which is preferable from the viewpoint of running costs.

Furthermore, compared to the tape type, the developing layer and reagent layer are not scratched and the developing layer and reagent layer are not distorted, so there is no reduction in measurement accuracy due to these factors. Accurate measurements can be made as well. In addition, since liquid samples can be spotted in parallel, multiple items can be measured at the same time, the measurement workability is good, and furthermore, the device itself can be easily miniaturized.

[0024] When the disc-shaped analytical element D is used, it is discarded, but if it is in the middle of being used, it may be removed from the turntable and stored. When reusing the device, it is easy to align the spotting means 1 with the spotting start position.

[0025]

[Effect] The disk-type analytical element according to the present invention is a disk-type analytical element that analyzes a specific component in the sample by spotting a liquid sample on the disk, and has a porous spread layer on the liquid sample spotting surface. Because it is constructed of Since no distortion occurs, there is no reduction in measurement accuracy due to these factors, and accurate measurements can be made just like with the slide type, and operation is extremely easy even when starting to use again after stopping measurement. Furthermore, it has the advantage that the device itself can be easily miniaturized.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing the principle of measurement using a disk-type analytical element according to the present invention.

[Explanation of symbols]

D　Disc-shaped analysis element 1. Spotting means 2 Photometering means 3 Temperature control means

Claims (1)

[Claims] Claim 1: A disk-type analysis element for analyzing a specific component in a sample by spotting a liquid sample on the disk, characterized in that a porous spreading layer is formed on the surface on which the liquid sample is spotted. A disk-shaped analytical element.