JP5858607B2 - Sample pad for in-vitro diagnostics - Google Patents

Description

  The present invention relates to a sample pad for an in vitro diagnostic agent (device) and an in vitro diagnostic agent using the same. More specifically, the present invention is a sample pad suitably used for a lateral flow type in-vitro diagnostic agent, which has a high liquid absorption rate per unit volume, a high liquid absorption ratio, a fast release time to the conjugate pad, and The present invention relates to a sample pad with a small amount of falling fibers.

In a test using an in vitro diagnostic agent, particularly a simple test agent, an immunological test using an antigen-antibody reaction is generally taken.
As the method, a lateral flow type membrane assay method is generally used, and a solution containing an object to be measured is passed in a vertical direction (liquid flow direction) through a film coated with a detection substance for the object to be measured. Detect or quantify by coloration. In other words, a liquid receiving part called a sample pad for dropping a solution containing an object to be measured, a conjugate pad for reacting the liquid supplied from the sample pad to be held by the detection part, and a vertical direction from the conjugate pad It consists of a membrane membrane for flowing liquid and a liquid absorbing pad for sucking and holding the liquid (see FIG. 1). As an example, specifically, a conjugate antibody is impregnated and dried in advance with a labeled antibody solution in which an antibody is labeled with a color-identifying substance such as an enzyme, a noble metal colloid, a colored latex, or a dye. A test solution containing a specimen such as blood, urine, sputum, nasal discharge, and cells containing an antigen is developed from a sample pad to a conjugate pad, and reacted with the antigen and the labeled antibody. In the detection part on the membrane membrane on which an antibody that recognizes an epitope different from the epitope of the antigen to be recognized is applied in advance, the conjugate of the antigen and the labeled antibody is supplemented and colored, so that the degree of coloration is increased. Measured as visual or optical change, and qualitative measurement or quantitative measurement of the antigen in the test solution is performed.
By using the above inspection methods, it is possible to easily and quickly inspect and diagnose the presence or absence of infection with a specific virus, determination of pregnancy, confirmation of illness, etc. Devices for that purpose and various simple in vitro diagnostic agents are available. Developed and marketed.

  In such inspection / diagnosis, filter paper, glass fiber nonwoven fabric, synthetic fiber nonwoven fabric, cellulose nonwoven fabric and the like have been conventionally used as a sample pad for dropping a solution containing an object to be measured (for example, Patent Document 1 below) And 2). However, in response to the recent expansion of the in-vitro diagnostic market, it is required to reduce the manufacturing cost of diagnostic reagents and to speed up the diagnostic time, and the sample pads are also required to have higher functionality.

  In reducing the manufacturing cost of a diagnostic agent, it is effective to shift the form of the test agent from a cassette type having an outer frame formed of resin or the like to a dipstick type without a frame. However, although a film is usually bonded to the outermost part of the dipstick type test agent, for example, since the fiber disclosed in Patent Document 2 is too thick, there is a problem that a gap is formed between the film and the fiber. Further, since the amount of the solution containing the object to be measured is too large, there is also a problem that the rapid release of the liquid from the sample pad to the conjugate pad is hindered, which is not preferable from the viewpoint of speeding up the diagnosis time.

On the other hand, if the thickness of the sample pad is made too thin, the retention and liquid feeding properties of the solution containing the object to be measured are lowered, causing variations in antigen-antibody reaction.
In addition, in short fiber nonwoven fabrics such as glass fiber nonwoven fabrics, the production environment is contaminated or damaged because it is easy to break and the falling fibers are easily generated, leading to a decrease in product yield and inspection accuracy. Glass fiber nonwoven fabrics have recently become a problem in terms of handleability and skin damage.

Japanese Patent No. 3304214 JP 2009-85838 A

  The problem to be solved by the present invention is to contribute to shortening examination time while maintaining the fiber physical properties suitable for lateral flow type in-vitro diagnostics, while reducing the manufacturing cost of diagnostic agents and accelerating the diagnostic time. It is an object of the present invention to provide a sample pad that has a high liquid absorption speed, a liquid absorption ratio, a release performance of a test liquid to a conjugate pad, and a reduction in yield.

  As a result of intensive studies to solve the above-mentioned problems and repeated experiments, the present inventors have optimized the material of the fibers constituting the nonwoven fabric used for the sample pad, the bulk density of the nonwoven fabric, and the thickness. The present inventors have found that the above problems can be solved by providing a sample pad having a liquid absorption speed, a liquid absorption amount, developability, and a high product yield, and has completed the present invention.

That is, the present invention is as follows.
[1] The bulk density is 0.06 to 1.0 g / cm ³ , the thickness is 0.07 to 0.90 mm, the basis weight is 25 to 100 g / m ² , and the number of shed fibers is 4000 pieces / m. less than ^2, a liquid absorption rate of 0.5～5.0Cm / sec, and catch and release index is in the range of 0.7 to 10.0, synthetic fibers and regenerated cellulose fibers are used together A sample pad for in vitro diagnostics composed of a cellulosic fiber nonwoven fabric , wherein the content of the regenerated cellulose fiber in the nonwoven fabric is 50 wt% or more and 70.8 wt% or less, and the synthetic fiber is The sample pad, which is a polyester fiber.

[ 2 ] The sample pad according to [1 ], wherein the cellulose fiber nonwoven fabric is a nonwoven fabric mainly composed of a continuous long fiber nonwoven fabric.

[ 3 ] An in vitro diagnostic agent comprising the sample pad according to [1] or [2] .

  The sample pad of the present invention has a high liquid absorption rate, expandability to the conjugate pad, and causes a decrease in yield by specifying the material of the fibers constituting the nonwoven fabric, the bulk density and thickness of the nonwoven fabric. It can contribute to suppression of generation | occurrence | production of a fallen fiber.

It is a figure which shows roughly an example of the test | inspection kit used for the performance test of the absorber for diagnostic agents.

Hereinafter, the present invention will be described in detail.
In view of the above problems, the sample pad of the present invention has a specific bulk density, thickness, liquid absorption rate, ratio of absorption capacity and release performance, the material of the fibers constituting the nonwoven fabric, the bulk density and thickness of the nonwoven fabric. It is possible to optimize performance by identifying the sample liquid, quickly absorb the dropped specimen liquid, and quickly release it to the conjugate pad, so that the test residual liquid hardly remains.

The bulk density of the nonwoven fabric which comprises the sample pad of this invention is 0.06-1.0 g / cm < ³ >. The bulk density can be appropriately changed according to the size of the sample pad, the amount of the specimen liquid, the type of examination, etc. However, if the bulk density is less than 0.06 g / cm ³ , the voids in the fiber will increase, so the specimen liquid sample pad When the internal movement and the spreadability to the conjugate pad are deteriorated and the bulk density exceeds 1.0 g / cm ³ , the fibers are too dense to allow the specimen liquid to penetrate the sample pad well. The liquid slips on the top. Therefore, the preferable range of the bulk density is 0.07 to 0.7 g / cm ³ , more preferably 0.1 to 0.5 g / cm ³ .

  The thickness of the nonwoven fabric constituting the sample pad of the present invention is 0.07 to 0.90 mm. The thickness can be appropriately changed depending on the size of the sample pad, the amount of the sample liquid, the type of examination, etc. However, if the thickness is less than 0.07 mm, the sample solution cannot be received sufficiently, and if it exceeds 0.9 mm, the sample solution This is not preferable because it will hold too much. The thickness is more preferably 0.1 to 0.8 mm.

As for the fabric weight of the nonwoven fabric which comprises the sample pad of this invention, 12-180 g / m < ² > is preferable, More preferably, it is 25-100 g / m < ² >.

  The liquid absorption speed of the sample pad of the present invention is determined by measuring the time required for the sample pad to reach a height of 10 cm according to the bileg water absorption method defined in JIS-L1907 and performing the evaluation. 0.5 to 5.0 cm / sec. The liquid absorption speed can be appropriately changed depending on the configuration, size, sample liquid volume, type of test, etc. of the sample pad. When the liquid absorption speed is less than 0.5 cm / second, the conjugate pad is added when the sample liquid is dropped. The specimen slides on the upper part of the sample pad before the specimen moves to the surface, and part of it overflows to the conjugate pad. On the other hand, if the liquid absorption speed exceeds 5.0 cm / second, the sample pad and the conjugate pad In other words, the test solution may remain on the boundary surface or the boundary surface between the conjugate pad and the membrane membrane, or the accuracy of the antigen-antibody reaction may be reduced even when there is no retention. The liquid absorption speed is preferably 0.6 to 4.5 cm / second.

  In the present specification, the term “cellulose fiber” refers to natural cellulose fibers such as hemp and cotton, regenerated cellulose fibers such as cupra, viscose rayon, and polynosic rayon, and purified cellulose fibers. Among them, regenerated cellulose fiber, purified cellulose fiber, particularly regenerated cellulose fiber with few impurities are preferable. The form of the cellulose fiber may be either a short fiber or a long fiber, but is preferably a long fiber, and more preferably a continuous long fiber with a small amount of fallen fiber.

In the present specification, the term “cellulosic fiber” refers to a fiber mainly composed of cellulose fiber. Cellulosic fibers may be composed of 100% cellulose fibers, and in order to control the form stability, liquid absorption speed, catch and release index when pretreating the sample pad, for example, polyethylene, polyester, etc. Synthetic fibers may be mixed. In this case, the content of the cellulose fiber in the cellulosic fibers constituting the nonwoven fabric in the present invention is preferably 50% by weight or more.
The synthetic fiber is not particularly limited as long as the desired physical properties of the sample pad described above are satisfied. Examples of the synthetic fiber include polyolefin-based, polyester-based, polyamide-based, and acrylic-based synthetic fibers. It may be used.

  The method for producing the cellulosic fiber nonwoven fabric is not particularly limited, and examples thereof include a spun bond method, a spun lace method, a melt blow method, a flash span method, a paper making method, an airlaid method, and the like, and further combining the respective methods. For example, spunbond / meltblown / spunbond (SMS), etc., and two or more types of cellulose fibers and synthetic fibers can be combined by heat treatment, bonding with a binder agent, heat fusion film, needle punch, water punch, etc. You may mix.

  The structure of the cellulosic fiber nonwoven fabric is not particularly limited as long as the desired physical properties of the sample pad described above are satisfied. However, it is quick that the cellulosic fibers are present in an area ratio of 50% or more on the surface where the sample liquid is dropped. It is more preferable at the point which hold | maintains and releases a liquid. Here, the area ratio is the area ratio of the cellulosic fibers present on the surface. For example, when composited with synthetic fibers, the cellulosic fibers are dyed and the structure is dyed with a dye that does not dye the synthetic fibers. The area of the stained portion relative to the unit surface area can be obtained by image analysis or the like.

  Hereinafter, an example is demonstrated about the manufacturing method of the cellulose fiber nonwoven fabric which concerns on this invention. A preferred embodiment is a regenerated cellulose continuous long fiber nonwoven fabric. For example, a cupra nonwoven fabric “Benlyse (registered trademark)” manufactured by Asahi Kasei Fibers Co., Ltd. (hereinafter also simply referred to as “cupra nonwoven fabric”) corresponds to this. .

  A method for producing a cupra nonwoven fabric is to extrude a stock solution in which a cotton linter whose degree of polymerization has been removed and dissolved in a copper ammonium solution is removed from a spinneret (spinner) having pores (stock solution discharge holes), At the same time, the inside of the funnel is dropped and deammoniated, so that the stock solution is solidified and stretched, and then shaken onto a net to form a web. At this time, the fiber shaken down to the net draws a Sin curve by vibrating in the direction perpendicular to the traveling direction while the net is moving. Stretching at the time of spinning can be 100 to 500 times, and the stretching ratio can be arbitrarily adjusted by changing the shape of the spinning funnel and the amount of spinning water flowing down. By changing the draw ratio, the single fineness and the strength of the nonwoven fabric can be changed.

  In forming the web of nonwoven fabric, the fiber arrangement to be shaken down to the net is obtained by uniformly changing the phase of the Sin curve in units of 3 to 3 to 10 layers in order to obtain the uniformity of the fiber arrangement. By doing so, a cellulosic nonwoven fabric having a very uniform fiber arrangement can be obtained. A multilayer nonwoven fabric having such a uniform fiber arrangement has a uniform fiber gap and uniform average pore diameter as a nonwoven fabric. If a nonwoven fabric having such a uniform pore size is densified, it is thin and dense. A nonwoven fabric having a uniform pore size is obtained.

  It is also possible to control low-molecular weight cellulose, so-called hemicellulose, remaining in a small amount in the stock solution by changing the amount of spinning water and the temperature. Further, by controlling the traveling speed and vibration width of the net, it is possible to control the fiber arrangement direction and control the strength, elongation and the like of the nonwoven fabric.

  The shape of the spinning funnel is preferably a rectangular shape, and the length of the spinning funnel to be flowed down is preferably 100 to 400 mm, and the slit width of the flowing down outlet is preferably 2 to 5 mm. The diameter of the stock solution discharge hole of the spinning nozzle is preferably 0.1 to 0.5 mm, and the shape is preferably a round shape. Moreover, it is preferable to laminate | stack a web from the meaning which ensures the uniformity of a nonwoven fabric, and the number of lamination | stacking is preferable 3-10 sheets. The web after lamination is regenerated or scoured with cellulose in a web state by, for example, the methods described in Japanese Patent Nos. 787914 and 877579, and then a fiber is entangled with a high-pressure water stream to produce a nonwoven fabric. . At this time, in order to impart design properties, it is possible to make holes or irregularities in the nonwoven fabric depending on the conditions of the high-pressure water flow and the net pattern disposed under and / or above the nonwoven fabric. The obtained nonwoven fabric can be obtained as a dried or wound product. Since the process from spinning to winding is performed in a series of steps, the fibers are connected continuously without being cut.

  Cellulosic fiber nonwoven fabrics contain various drugs and powders in a range that does not affect the antigen-antibody reaction and the binding with labeled antibodies, or part of the cellulose is modified to control hydrophilicity / water repellency and water absorption ratio. You may let them. Cellulosic fiber nonwoven fabrics contain, for example, surfactants, water repellents, resins for fixing fibers, antibacterial agents, preservatives, antioxidants, etc., and some cellulose functional groups are carboxymethylated , Carboxyethylation, oxidation, etc. may be modified.

In the present specification, the “catch and release index” is calculated by the following formula:
Catch and release index = water absorption magnification ÷ release time The water absorption magnification is a value obtained by the following measurement method.
The sample pad is left in a room controlled at 20 ° C. and 65% RH for 15 hours to adjust the humidity, and the sample cut into 10 cm squares is weighed (W1 (g)).
A sample is placed on a wire mesh having a wire diameter of 0.5 mm and 10 mesh, and the wire mesh is immersed in water at 20 ° C. for 30 seconds. Thereafter, the sample is left in the air for 10 minutes while being kept horizontal on the wire mesh, drained, and weighed again (referred to as W2 (g)). Calculate the water absorption ratio by the following formula:
Water absorption magnification = (W2-W1) / W1

  The water absorption ratio can be changed as appropriate depending on the size of the sample pad, the amount of sample liquid, the type of test, etc., but the range is 7.0 to 55.0 times in order to produce efficient absorption and release of the sample. It is preferable, and more preferably 10.0 to 35.0 times.

  Also, in this specification, “release time” means that the test solution is completely transferred from the sample pad to the conjugate pad when 50 μL of the test solution is dropped on the sample pad by preparing the following diagnostic kit. Time (unit is minutes).

  The “catch and release index” indicates the property of quickly absorbing the dropped specimen liquid and releasing it quickly to the conjugate pad. The catch and release index of the cellulosic nonwoven fabric constituting the sample pad of the present invention is 0.7 to 10.0, more preferably 0.8 to 8.0. The catch and release index can be adjusted by controlling the bulk density of the nonwoven fabric according to the material of the cellulosic fiber used for the sample pad, the size of the sample pad, the amount of the specimen liquid, the type of the test liquid, and the like.

  A catch-and-release index of less than 0.7 means a longer time for the test solution to transfer from the sample pad to the conjugate pad, which not only hinders faster test times, Depending on the amount of dripping, the sample liquid slides on the sample pad, and an accurate test cannot be performed. . On the other hand, if the catch and release index exceeds 10.0, it means that the development time is remarkably short. In this case, the specimen liquid in which the antigen and the antibody are bound is transferred from the conjugate pad to the membrane membrane. Since the test solution is transferred from the sample pad to the conjugate pad at a rate higher than the transfer rate, the solution may remain on the conjugate pad or may overflow.

  In order to achieve a desired catch and release index, the above-mentioned regenerated cellulose continuous fiber (Benlyse (registered trademark)) is preferable as the fiber material. Benlyse (registered trademark) is a regenerated cellulose continuous long fiber in which cotton linter is once dissolved in a copper ammonia complex as described above, and cellulose is reconstructed by subsequent solvent removal, and the crystallinity is low among cellulosic fibers. Since it has many hydroxyl groups and many fine vacancies, it is highly responsive to moisture. Since Benlyse (registered trademark) generally has an official moisture content of 11% and can absorb liquid about 13 times its own weight, it is also suitable for improving the catch performance of the test liquid in the present invention. In addition, since Benize (registered trademark) is a continuous long fiber in which fibers are connected one by one, the fiber arrangement is highly anisotropic. For this reason, the liquid can quickly move between the fibers, which is suitable for improving the release performance of the test liquid.

  In this specification, the term “number of fallen fibers” means that a sample of 25 cm × 25 cm is put in 300 ml of pure water, left to stand for 2 minutes, and the remaining liquid from which the sample has been taken out is filtered with black filter paper (ADVANTEC NO131), The filter paper after filtration is placed in a thermostatic chamber (20 ° C., 65% RH) for 12 hours, dried, then counted and measured with a video microscope, and the number of shed fibers having a size of 100 μm or more per unit square meter.

In the present invention, the number of shed fibers is preferably less than 5000 / m ² , more preferably less than 4000 / m ² , and still more preferably less than 3000 / m ² . If the number of shed fibers exceeds 10,000 / m ² , the fibers easily fall off, and depending on the type of the test solution, the shed fibers may collect at the interface between the sample pad and the conjugate pad, impairing the spreadability. In addition, the yield is deteriorated by contaminating the periphery of the production line during production, which is not preferable. Since the number of fallen fibers is preferably smaller, the lower limit is 1 / m ² or more.

  The in-vitro diagnostic agent (device) or test kit according to the present invention is a method for simply detecting the presence or absence of an antigen contained in a nasal swab, nasal aspirate, or pharyngeal swab. The types of diagnostic agents (devices) or kits mainly include lateral flow type and flow through type, and this sample pad is particularly suitable for lateral flow type, and particularly suitable for dip stick type. It is.

The shape of the in-vitro diagnostic agent (device) or test kit according to the present invention is not particularly limited. The width (perpendicular to the liquid flow) direction is not a problem as long as it is larger than the width of the conjugate pad. If the width is too narrow, there is a possibility that the test solution may wrap around from the end of the sample pad.
In the present invention, well-known substances can be used and limited as diluted specimen liquids, conjugate pads, water absorption pads, membrane membranes, standard antibodies, color identification substances, etc. used in in vitro diagnostic agents (devices) or test kits. It is not something.

  In addition to the labeled antibody, the diluted sample solution may contain a dilute solution, various surfactants, salt content, etc., and before dropping, remove solids at the time of sample collection or foreign components contained in the standard antibody. In order to remove, it may be used after filtering with a filter or the like.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.
In addition, the use member used for the Example etc., the test liquid, the measuring method, the evaluation method were as follows.
Hereafter, the member and test solution which were used for evaluation of the Example of this invention are demonstrated.
(A) Antibody-immobilized membrane membrane On a nitrocellulose membrane membrane (pore size 60 μm), a mouse anti-influenza A virus antibody solution was applied so as to form a line with a width of 2 mm and dried, and Mariarim AFB-1521 and The membrane was blocked with a Tris-HCl buffer to obtain an antibody-immobilized membrane. The obtained antibody-immobilized membrane was cut out to have a width of 5 mm and a length of 30 mm. The antibody immobilization position was perpendicular to the flow direction and was 20 mm long.

(B) Labeled antibody A colloidal gold of about 60 nm and an antibody recognizing an epitope different from the antibody used for the antibody-immobilized membrane membrane were mixed in a borate buffer (PH9.0), and then BSA 10% After blocking by adding an aqueous solution, a labeled antibody was obtained by centrifugation.

(C) Dilution test solution for color development The above labeled antibody is mixed with PBS containing 0.2% Tween20, 1% sucrose and 0.2BSA, and diluted containing influenza A purified antigen (Kitakyusyu / 159/93 strain) A sample solution (virus concentration of 1 × 10 ⁶ in TCID50 / test unit) was added and adjusted.

(D) Impregnation of labeled antibody into conjugate pad Polyester conjugate pad (Pole, type 6613) 5 μm × 5 mm impregnated with 10 μl of the labeled antibody of (b) above and freeze-dried conjugate A gate pad was obtained.

(E) Simple diagnostic agent (device) (diagnostic kit, test kit)
As shown in FIG. 1, an antibody-immobilized membrane is pasted on a backing sheet, a conjugate pad is placed at the end of the membrane, and a water absorbing pad (5 mm wide, 20 mm long, membrane membrane) is placed at the other end. 5mm No526 Advantech Co., Ltd.), the sample pad of the example and the comparative example (5 mm width 15 mm, conjugate pad overlap 5 mm) is placed so as to overlap the conjugate pad, and finally from the top with a transparent tape A dipstick type inspection kit was obtained by pasting and fixing so as to cover the mount.

(1) Weight per unit area (g / m ² )
A non-woven fabric having an area of 0.5 m ² or more is dried at 105 ° C. until a constant weight is reached, then left in a constant temperature room at 20 ° C. and 65% RH for 16 hours or more, and the weight is measured. The weight (g / m ² ) was determined.

(2) Thickness A load was measured as 1.96 kPa in a thickness test according to JIS-L1096 (unit: mm).

(3) Bulk density The bulk density was calculated from the weight per unit area and thickness (unit: g / cm ³ ).

(4) Liquid absorption speed Using the bi-leg water absorption method defined in JIS-L1907, the time required to reach a height of 10 cm was measured and evaluated by allowing the sample pad to meet the direction in which the test liquid flows.
The sample was 200 mm (length) × 25 mm (width), and was measured after leaving it in a room controlled at 20 ° C. and 65% RH for 15 hours to adjust the humidity.
Liquid absorption speed (cm / second) = 10 cm / (10 cm height arrival time (second))

(5) Catch and release index The water absorption magnification and deployment completion time (release time) were measured and calculated by the following formula:
Catch and release index = water absorption ratio ÷ release time

Water Absorption Magnification Evaluation Method The absorber was allowed to stand for 15 hours in a room controlled at 20 ° C. and 65% RH, and the sample cut into 10 cm square was weighed (referred to as W1 (g)).
A sample was placed on a wire mesh of wire diameter 0.5 mm and 10 mesh, and the wire mesh was immersed in water at 20 ° C. for 30 seconds. Thereafter, the sample was left in the air for 10 minutes while being kept horizontal on the wire mesh, drained, weighed again (referred to as W2 (g)), and the water absorption ratio was determined by the following formula:
Water absorption magnification = (W2-W1) / W1

Release Time Evaluation Method The time (release time) at which the test solution completely transferred from the sample pad to the conjugate pad when 50 μL of the color developing diluted test solution was dropped onto the sample pad of the simple diagnostic agent was measured.

(6) Number of fallen fibers A sample of 25 cm × 25 cm was put in 300 ml of pure water and allowed to stand for 2 minutes. The remaining liquid from which the sample was taken out was filtered through black filter paper (ADVANTEC NO131). The filtered paper after filtration was placed in a temperature-controlled room (20 ° C., 65% RH) for 12 hours and dried, and then the number of shed fibers having a size of 100 μm or more was measured with a video microscope (unit: pieces / m ² ). .

(7) Product yield (e) In producing the simple diagnostic reagent (device) (diagnostic reagent kit, test kit), calculate the loss rate associated with pass / fail judgment in the sample pad breakage or test liquid deployment test. The product yield was measured.

(8) Comprehensive evaluation The above items (1) to (7) were comprehensively determined according to the following evaluation criteria.
A: Product yield and diagnostic kit performance are both excellent.
○: Both product yield and diagnostic kit performance are excellent.
Δ: Product yield is excellent, but diagnostic kit performance is poor.
×: Both diagnostic kit performance and product yield are poor.

[Example 1]
The average fiber diameter of 12 [mu] m, an average basis weight 27.5 g / ^{m 2} of regenerated cellulose continuous long-fiber nonwoven fabric and an average fiber diameter of 10 [mu] m, an average basis weight 12.0 g / ^m and the ^second polyester non-woven fabric is hydroentangled at a water jet nonwoven fabric, the average A regenerated cellulose continuous long-fiber nonwoven fabric having a fiber diameter of 12 μm and an average basis weight of 38.0 g / m ² was prepared. A perforated polyethylene film is placed between two prepared nonwoven fabrics, and both the upper and lower rolls are made of stainless steel (SUS329) calendering machine and have the basis weight, bulk density, and thickness shown in Table 1 below. Thus, the thermal calendar process of 130 degreeC was performed, and the nonwoven fabric was produced. A diagnostic kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

[ Reference Example 2]
A regenerated cellulose continuous long-fiber nonwoven fabric having an average fiber diameter of 12 μm and an average basis weight of 57.2 g / m ² was prepared. Both the upper and lower rolls were subjected to thermal calendering so as to have the basis weight, bulk density, and thickness shown in Table 1 below using a stainless steel (SUS329) calendering machine to produce a nonwoven fabric. An inspection kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

[ Reference Example 3]
A nonwoven fabric was prepared in the same manner as in Reference Example 2 except that a regenerated cellulose continuous long-fiber nonwoven fabric having an average fiber diameter of 12 μm and an average basis weight of 72.0 g / m ² was prepared. An inspection kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

[ Reference Example 4]
A nonwoven fabric was prepared in the same manner as in Reference Example 2 except that a regenerated cellulose continuous long-fiber nonwoven fabric having an average fiber diameter of 12 μm and an average basis weight of 27.5 g / m ² was prepared. An inspection kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

[Comparative Example 1]
A nonwoven fabric was prepared in the same manner as in Reference Example 2 except that a regenerated cellulose continuous long-fiber nonwoven fabric having an average fiber diameter of 12 μm and an average basis weight of 28.0 g / m ² was prepared. An inspection kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

[Comparative Example 2]
A nonwoven fabric was prepared in the same manner as in Reference Example 2 except that a regenerated cellulose continuous long-fiber nonwoven fabric having an average fiber diameter of 12 μm and an average basis weight of 120.0 g / m ² was prepared. An inspection kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

[Comparative Example 3]
Nonwoven fabrics having physical properties shown in Table 1 below were prepared by the kino cloth method, which is one of the dry airlaid nonwoven fabric manufacturing methods, in which wood pulp having an average fiber diameter of 20 μm is dispersed and laminated in the air together with a hydrophilic binder. An inspection kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

[Comparative Example 4]
After laminating wood pulp, non-woven fabrics having the physical properties shown in Table 1 below were prepared in the same manner as in Comparative Example 3, except that rayon fibers having an average fiber diameter of 15 μm were laminated on both surfaces of the wood pulp outer layer. An inspection kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

[Comparative Example 5]
Nonwoven fabrics having physical properties shown in Table 1 below were prepared using glass fiber nonwoven fabrics produced by papermaking. An inspection kit was prepared using this nonwoven fabric as a sample pad, and the above (1) to (7) were evaluated. The results are shown in Table 1 below.

The sample pads of Example 1 and Reference Example 2 showed very good catch and release performance and product yield (overall evaluation ◎).
The sample pads of Reference Examples 3 and 4 showed excellent catch and release performance and product yield (overall evaluation ○).
The sample pads of Comparative Examples 1 and 2 showed excellent product yield, but the kit performance was poor (overall evaluation Δ) because the liquid absorption speed was too fast or too slow.
About Comparative Examples 3-5, there were many drop-off fibers, the product yield was also bad, and also the kit performance was also bad (comprehensive evaluation x).

  The sample pad of the present invention has a high liquid absorption rate, a balance between the liquid absorption amount and the developability by specifying the fiber material of the nonwoven fabric constituting the sample pad, the bulk density and thickness of the nonwoven fabric, and the product yield is high. It has been improved. Therefore, the sample pad of the present invention can contribute to the reduction of diagnostic agent manufacturing cost and the improvement of the performance of the test kit, and can be used for various lateral flow test kits.

1 Membrane film 1a Application part (colored part)
2 Conjugate pad 3 Sample pad 4 Water absorbing pad 5 Mount

Claims (3)

The bulk density is 0.06 to 1.0 g / cm ³ , the thickness is 0.07 to 0.90 mm, the basis weight is 25 to 100 g / m ² , and the number of fallen fibers is less than 4000 pieces / m ² . Cellulosic fiber in which regenerated cellulose fiber and synthetic fiber are mixed, having a liquid absorption rate of 0.5 to 5.0 cm / sec and a catch and release index in the range of 0.7 to 10.0 A sample pad for in vitro diagnostics composed of a nonwoven fabric , wherein the content of the regenerated cellulose fiber in the nonwoven fabric is 50 wt% or more and 70.8 wt% or less, and the synthetic fiber is a polyester fiber The sample pad.   The sample pad according to claim 1, wherein the cellulose-based fiber nonwoven fabric is a nonwoven fabric mainly composed of a continuous long-fiber nonwoven fabric. An in vitro diagnostic agent comprising the sample pad according to claim 1 or 2 .

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