Specimen collection container, specimen separation method, and article accommodating specimen collection container

Abstract

Provided is a specimen collection container capable of reducing the amount of high-specific-gravity components in a specimen entering a partition wall and the amount of the high-specific-gravity components being deposited on the upper surface of the partition wall.　The specimen collection container according to the present invention is used by being set in a centrifugal separator after a specimen is collected, and comprises: an inner container having an opening end and a closed end; an outer container having an opening end and a closed end; a plug body; and a composition for specimen separation having thixotropy. The plug body closes the opening end of the outer container. The inner container and the plug body are not in contact with each other, and the inner container and the outer container are not in contact with each other. The composition for specimen separation is disposed between the outer surface of the inner container and the inner surface of the outer container, and is in contact with the outer surface of the inner container and the inner surface of the outer container. The specific gravity of the composition for specimen separation at 25°C is 1.025 or more and less than 1.050. During a centrifugal separation operation in the centrifugal separator, the inner container moves from the opening end side of the outer container toward the closed end side and at least a part of the composition for specimen separation flows into the inner container.

Description

Specimen collection container, specimen separation method and specimen collection container contents

[0001] The present invention relates to a specimen collection container used by being set in a centrifugal separator after collecting a specimen. The present invention also relates to a specimen separation method using the above specimen collection container. The present invention also relates to a specimen collection container contents including the above specimen collection container.

[0002] There is known a specimen collection container that is used by being set in a centrifugal separator after collecting a specimen. The above specimen collection container contains a thixotropic specimen separation composition. In the above specimen collection container, the specimen can be separated into a layer with a relatively high specific gravity (high specific gravity component layer) and a layer with a relatively low specific gravity (low specific gravity component layer) by centrifugation. At this time, the specimen separation composition is located between the high specific gravity component layer and the low specific gravity component layer, and functions as a partition wall separating the two layers.

[0003] As the above specimen collection container, blood collection tubes containing a blood separation composition (specimen separation composition) as described in the following Patent Documents 1 and 2 are widely used. In the above blood collection tube, after blood is collected, centrifugation can be performed to separate the blood into a plasma layer and a blood cell layer, or to separate the blood into a serum layer and a clot layer.

[0004] In addition, FIG. 1 of the following Patent Document 3 discloses a vacuum assembly 11 including a tube 12, a specific member 40 arranged inside the tube 12, and a gel-like substance 30 arranged at the bottom of the tube 12. Patent Document 3 describes a configuration in which, after a specimen is collected in the vacuum assembly 11 and centrifuged, the member 40 moves downward and the gel-like substance 30 moves upward, thereby separating the specimen into a layer 64 with high specific gravity and a layer 62 with low specific gravity.

[0005] JP 2002-333443 A JP 56-166956 A US 3920549A

[0006] In a conventional general specimen collection container, the above specimen separation composition is housed at the bottom of the specimen collection container. This state is shown in FIG. 8. The specimen collection container 100 shown in FIG. 8 includes a container body 200 and a specimen separation composition 400.

[0007] When a sample is collected in a conventional sample collection container as shown in Figure 8 and centrifuged, the sample separation composition and the high-density components in the sample move in opposite directions. Therefore, during centrifugation, the sample separation composition and the high-density components in the sample may collide, or the high-density components may be stirred up as a result of these collisions. Consequently, the high-density components in the sample may become mixed into the partitions formed by the sample separation composition or accumulate on the upper surface of the partitions.

[0008] Furthermore, the vacuum assembly 11 described in Patent Document 3 is intended to collect a considerably large amount of sample relative to the volume of the member 40. Therefore, even with the vacuum assembly 11 described in Patent Document 3, during the centrifugal separation operation, the gel-like substance 30 that has moved above the member 40 will collide with the high-density components in the sample. As a result, the high-density components in the sample may be mixed into the partition wall formed by the gel-like substance 30 or deposited on the upper surface of the partition wall. The vacuum assembly 11 described in Patent Document 3 is intended to collect a considerably large amount of sample relative to the volume of the member 40, so the gel-like substance 30 will not flow into the member 40 during the centrifugal separation operation.

[0009] If high-density components are mixed into the septum or accumulate on the upper surface of the septum, these high-density components may migrate to unintended layers. For example, when blood is separated into a plasma layer and a blood cell layer using a conventional sample collection container, blood cells mixed in the septum may migrate to the plasma layer, or blood cells accumulated on the upper surface of the septum may migrate to the plasma layer. Also, for example, when blood is separated into a serum layer and a blood clot layer using a conventional sample collection container, blood cells mixed in the septum (free blood cells not incorporated into the blood clot) may migrate to the serum layer, or blood cells accumulated on the upper surface of the septum (free blood cells not incorporated into the blood clot) may migrate to the serum layer.

[0010] The object of the present invention is to provide a sample collection container that can reduce the amount of high-density components in the sample that mix into the partition wall and accumulate on the upper surface of the partition wall. The present invention also aims to provide a method for separating a sample using the above-mentioned sample collection container. Furthermore, the present invention also aims to provide a sample collection container containing the above-mentioned sample collection container.

[0011] This specification discloses the following sample collection container, sample separation method, and contents of the sample collection container.

[0012] Item 1. A sample collection container used by setting it in a centrifuge after collecting a sample, comprising: an inner container having an open end and a closed end; an outer container having an open end and a closed end; a stopper; and a thixotropic sample separation composition, wherein the inner container is positioned inside the outer container; the stopper closes the open end of the outer container; the inner container and the stopper are not in contact; the inner container and the outer container are not in contact; the sample separation composition is positioned between the outer surface of the inner container and the inner surface of the outer container; the sample separation composition is in contact with the outer surface of the inner container and the inner surface of the outer container; the specific gravity of the sample separation composition at 25°C is 1.025 or more and less than 1.050; and during the centrifugation operation in the centrifuge, the inner container moves from the open end side of the outer container toward the closed end side of the outer container, and at least a portion of the sample separation composition flows into the inner container.

[0013] Item 2. The specimen collection container according to Item 1, wherein the volume of the inner container is less than the sum of the volume of the specimen separation composition and the volume of the specimen to be collected.

[0014] Item 3. A blood collection container, as described in Item 1 or 2.

[0015] Item 4. A method for separating a sample into a high-density component layer and a low-density component layer using a sample collection container described in any one of Items 1 to 3, comprising the steps of: (1) collecting a sample in the sample collection container; and (2) setting the sample collection container from which the sample has been collected in a centrifuge and performing a centrifugation operation, wherein step (2) comprises: (2A) moving the inner container from the open end side of the outer container toward the closed end side of the outer container; (2B) allowing at least a portion of the sample separation composition to flow into the inner container; and (2C) forming a partition wall separating the high-density component layer and the low-density component layer with the sample separation composition that has flowed into the inner container.

[0016] Item 5. The method for separating a specimen as described in Item 4, wherein the specimen is blood.

[0017] Item 6. A sample collection container comprising a packaging member, a sample collection container according to any one of items 1 to 3, and instructions for using the sample collection container, wherein the sample collection container is housed within the packaging member, and the instructions contain the conditions for centrifugal separation in a centrifugal apparatus, either in written form or recorded electronically.

[0018] The sample collection container according to the present invention can reduce the amount of high-density components in the sample that mix into the partition wall and accumulate on the upper surface of the partition wall.

[0019] Figure 1 is a schematic cross-sectional view showing a sample collection container according to one embodiment of the present invention. Figure 2 is a cross-sectional view showing an example of an inner container usable in the present invention. Figures 3(a) to (c) are cross-sectional views illustrating a method for separating a sample using the sample collection container shown in Figure 1. Figures 4(d) to (f) are cross-sectional views illustrating a method for separating a sample using the sample collection container shown in Figure 1. Figure 5 is a cross-sectional view showing an example of separating a sample into a high-density component layer and a low-density component layer using the sample collection container of the present invention. Figure 6 is a cross-sectional view showing an example of separating a sample into a high-density component layer and a low-density component layer using the sample collection container of the present invention. Figure 7 is a cross-sectional view showing an example of separating a sample into a high-density component layer and a low-density component layer using the sample collection containers obtained in Comparative Examples 3, 4, and 6. Figure 8 is a cross-sectional view showing a conventional sample collection container. Figure 9 is an image diagram that visually illustrates the criteria for judgment in the examples.

[0020] The details of the present invention will be described below.

[0021] [Sample Collection Container] The sample collection container according to the present invention is used by setting it in a centrifuge after collecting the sample. The sample collection container according to the present invention comprises an inner container having an open end and a closed end, an outer container having an open end and a closed end, a stopper, and a thixotropic sample separation composition.

[0022] In the sample collection container according to the present invention, the inner container is positioned inside the outer container. In the sample collection container according to the present invention, the stopper closes the open end of the outer container. In the sample collection container according to the present invention, the inner container and the stopper are not in contact, and the inner container and the outer container are not in contact. In the sample collection container according to the present invention, the sample separation composition is positioned between the outer surface of the inner container and the inner surface of the outer container. In the sample collection container according to the present invention, the sample separation composition is in contact with the outer surface of the inner container and is also in contact with the inner surface of the outer container.

[0023] In the sample collection container according to the present invention, the specific gravity of the sample separation composition at 25°C is 1.025 or more and less than 1.050.

[0024] In the sample collection container according to the present invention, during the centrifugation operation in the centrifuge, the inner container moves from the open end side of the outer container toward the closed end side of the outer container, and at least a portion of the sample separation composition flows into the inner container.

[0025] By collecting a sample in the sample collection container according to the present invention and placing it in a centrifuge, the sample can be separated into a high-density component layer (a layer with a relatively high specific gravity) and a low-density component layer (a layer with a relatively low specific gravity). A partition wall is formed between the high-density component layer and the low-density component layer by the sample separation composition that flows into the inner container. Since the sample collection container according to the present invention is equipped with the above configuration, the amount of high-density component in the sample that mixes into the partition wall and the amount that accumulates on the upper surface of the partition wall can be reduced.

[0026] Hereinafter, in this specification, the open end of the outer container in the sample collection container may be referred to as the "upper side," and the closed end of the outer container in the sample collection container may be referred to as the "lower side."

[0027] The reasons why the above-mentioned effects are achieved in the specimen collection container according to the present invention are as follows:

[0028] By collecting a sample in the sample collection container according to the present invention and placing it in a centrifuge for centrifugation, the high-density components in the sample begin to settle. Furthermore, by collecting a sample in the sample collection container according to the present invention and placing it in a centrifuge for centrifugation, the inner container moves from the open end of the outer container toward the closed end of the outer container, and at least a portion of the sample separation composition flows into the inner container from the open end. The flow of the sample separation composition into the inner container means that a high-density component layer is formed within the inner container, and that the volume of the inner container is greater than the volume of the high-density component layer. Therefore, in the sample collection container according to the present invention, most of the high-density components can move into the inner container before the sample separation composition can flow into the inner container. In other words, in the sample collection container according to the present invention, the sample separation composition and the high-density components in the sample move in the same direction (from top to bottom) within the inner container, so collisions between the sample separation composition and the high-density components in the sample are suppressed. Therefore, the amount of high-density components in the sample that enter the septum can be reduced.

[0029] Furthermore, in the sample collection container according to the present invention, the sample separation composition and the high-density components in the sample move in the same direction within the inner container, thus suppressing the scattering of high-density components and preventing the high-density components from mixing into the low-density component layer. As a result, the amount of high-density components in the sample that accumulates on the upper surface of the partition wall can also be reduced.

[0030] Furthermore, in the sample collection container according to the present invention, collisions between the sample separation composition and the high-density components in the sample are suppressed, thereby reducing damage to the high-density components.

[0031] The sample collection container according to the present invention reduces the risk of contamination of the low-density component layer by high-density components. For example, when testing components contained in the low-density component layer, the accuracy of the test can be improved.

[0032] Furthermore, in sample collection containers, a certain amount of time may pass between the separation of the sample into a low-density component layer and a high-density component layer and before it is subjected to testing. During this time, the high-density component (e.g., blood cells) may disintegrate due to death or other reasons, and the contents of the high-density component may leak out. In the sample collection container according to the present invention, the risk of contamination of the low-density component layer by the high-density component can be reduced, so even if a certain amount of time has passed between the separation of the sample into a low-density component layer and a high-density component layer and before it is subjected to testing, high testing accuracy can be maintained.

[0033] The sample collection container according to the present invention can achieve the above-mentioned effects regardless of the type of centrifugal rotor. The sample collection container according to the present invention can achieve the above-mentioned effects whether it is an angle rotor or a swing rotor.

[0034] Furthermore, in the sample collection container according to the present invention, since the sample separation composition is placed between the outer surface of the inner container and the inner surface of the outer container, unintended leakage during storage of the sample collection container can be suppressed. For example, even if the sample collection container is stored tilted at an angle in a relatively high-temperature environment, leakage of the sample separation composition can be effectively suppressed.

[0035] Specific embodiments of the present invention will be described below with reference to the drawings.

[0036] Figure 1 is a schematic cross-sectional view showing a sample collection container according to one embodiment of the present invention.

[0037] The sample collection container 10 shown in Figure 1 is used after the sample has been collected and placed in a centrifuge. The sample collection container 10 is used to separate the sample into a high-density component layer (a layer with a relatively high specific gravity) and a low-density component layer (a layer with a relatively low specific gravity).

[0038] The sample collection container 10 comprises an inner container 1, an outer container 2, a stopper 3, and a sample separation composition 4.

[0039] The inner container 1 has an open end 1a and a closed end 1b. The open end 1a of the inner container 1 is one end in the length direction of the inner container 1, and the closed end 1b of the inner container 1 is the other end in the length direction of the inner container 1. In the inner container 1, the distance between the open end 1a and the closed end 1b is the length of the inner container 1. Also, the inner container 1 has an inner surface 1c and an outer surface 1d.

[0040] The outer container 2 has an open end 2a and a closed end 2b. The open end 2a of the outer container 2 is one end in the length direction of the outer container 2, and the closed end 2b of the outer container 2 is the other end in the length direction of the outer container 2. In the outer container 2, the distance between the open end 2a and the closed end 2b is the length of the outer container 2. Also, the outer container 2 has an inner surface 2c and an outer surface 2d.

[0041] The inner container 1 is arranged inside the outer container 2. The inner container 1 and the outer container 2 are not in contact with each other. The outer surface 1d of the inner container 1 and the inner surface 2c of the outer container 2 are not in contact with each other.

[0042] The plug 3 closes the open end 2a of the outer container 2. The plug 3 and the inner container 1 are not in contact with each other.

[0043] The specimen separating composition 4 has thixotropic properties. After centrifugation, the specimen separating composition 4 is located between a high specific gravity component layer and a low specific gravity component layer, and is a composition that functions as a partition wall separating the two layers. The specimen separating composition 4 is a partition wall-forming composition. The specific gravity of the specimen separating composition 4 is generally smaller than the specific gravity of the high specific gravity component layer and larger than the specific gravity of the low specific gravity component layer.

[0044] The specimen separating composition 4 is arranged between the outer surface 1d of the inner container 1 and the inner surface 2c of the outer container 2. The specimen separating composition 4 is not in contact with the inner surface 1c of the inner container 1. The specimen separating composition 4 is in contact with the outer surface 1d of the inner container 1. The specimen separating composition 4 is in contact with the inner surface 2c of the outer container 2.

[0045] The inner container 1 is embedded in the specimen-separating composition 4 such that the open end 1a of the inner container 1 is exposed. Since the specimen-separating composition 4 has thixotropic properties, the specimen-separating composition 4 can hold the inner container 1. The entire outer surface 1d of the inner container 1 is in contact with the specimen-separating composition 4. The weight of the inner container 1 is smaller than the buoyant force acting on the inner container 1.

[0046] During centrifugation in a centrifugal separator after collecting a specimen, the inner container 1 moves from the open end 2a side of the outer container 2 toward the closed end 2b side of the outer container 2, and at least a part of the specimen-separating composition 4 flows into the inner container 1.

[0047] The internal pressure of the specimen collection container 10 is less than 1 atm. The internal pressure of the specimen collection container 10 is reduced pressure. This allows a predetermined amount of specimen to be easily collected into the specimen collection container 10.

[0048] Hereinafter, details of each member of the specimen collection container according to the present invention will be described.

[0049] (Inner container and outer container) The specimen collection container includes an inner container. The specimen collection container includes an outer container. The shapes of the inner container and the outer container are not particularly limited, respectively. The inner container is preferably a tubular container. The outer container is preferably a tubular container. The inner container is preferably a container having a similar shape to the outer container.

[0050] The inner container is arranged inside the outer container. The length of the inner container (the distance between the open end and the closed end of the inner container) is shorter than the length of the outer container (the distance between the open end and the closed end of the outer container). The outer diameter of the open end of the inner container is smaller than the inner diameter of the open end of the outer container. Note that a ridge may be provided on the outer surface of the inner container.

[0051] Let L be the length of the outer container (the distance between the open end and the closed end of the outer container). The length of the inner container (the distance between the open end and the closed end of the inner container) is preferably 0.3 L or more, more preferably 0.5 L or more, even more preferably 0.7 L or more, preferably 0.9 L or less, and more preferably 0.8 L or less. When the length of the inner container is above the lower limit and below the upper limit, the effects of the present invention can be exhibited even more effectively.

[0052] The inner container and the outer container are not in contact. More specifically, the outer surface of the inner container and the inner surface of the outer container are not in contact.

[0053] The shortest distance between the outer surface of the inner container and the inner surface of the outer container is preferably 0.2 mm or more, more preferably 0.3 mm or more, more preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1 mm or less. If the shortest distance is above the lower limit and below the upper limit, the sample separation composition can be moved well during the centrifugation operation in the centrifuge. If the shortest distance is below the upper limit, the amount of sample separation composition remaining between the outer surface of the inner container and the inner surface of the outer container after the centrifugation operation (the amount of sample separation composition that does not contribute to the formation of the partition wall) can be reduced.

[0054] Of the 100% area of ​​the outer surface area of ​​the inner container, the area in contact with the sample separation composition is preferably 5% or more, more preferably 10% or more, and even more preferably 30% or more. If the area in contact with the sample separation composition is greater than or equal to the lower limit, the effects of the present invention can be exhibited even more effectively. The area in contact with the sample separation composition of the 100% area of ​​the outer surface area of ​​the inner container may be 100%, less than 100%, or 80% or less.

[0055] The volume of the inner container described above may be smaller or larger than the volume of the sample being collected.

[0056] The volume of the inner container is preferably smaller than the sum of the volume of the sample separation composition and the volume of the sample to be collected. In this case, the open end of the inner container will not be exposed from the low-density component layer after centrifugation. Therefore, the sample separation composition will not easily float on the surface of the low-density component layer after the centrifugation operation.

[0057] When the sample is separated into a high-density component layer and a low-density component layer, it is preferable that the volume of the inner container is larger than the volume of the high-density component layer. In this case, the effects of the present invention can be exhibited even more effectively.

[0058] Let V be the volume of the outer container. The volume of the inner container is preferably 0.2V or more, more preferably 0.3V or more, even more preferably 0.4V or more, preferably 0.7V or less, and more preferably 0.6V or less. The effects of the present invention can be exhibited more effectively when the volume of the inner container is above the lower limit and below the upper limit. The volume V of the outer container is the volume before the inner container is placed and before the sample separation composition is placed (the volume of the outer container itself). The volume of the inner container is the volume of the inner container itself.

[0059] The inner container may have a tapered region at its open end where the inner diameter gradually decreases from the open end towards the closed end. If the inner container has the tapered region, the sample separation composition is more likely to flow into the inner container during the centrifugation operation in the centrifuge.

[0060] Figure 2 is a cross-sectional view showing an example of an inner container that can be used in the present invention.

[0061] Unlike the inner container 1 shown in Figure 1, the inner container 1A shown in Figure 2 has a tapered region R at its open end 1Aa where the inner diameter gradually decreases from the open end 1Aa towards the closed end 1Ab.

[0062] The materials for the inner container and the outer container are not particularly limited. Examples of materials for the inner container and the outer container include thermoplastic resins such as polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyacrylate, and polyacrylonitrile; thermosetting resins such as unsaturated polyester resins, epoxy resins, and epoxy-acrylate resins; modified natural resins such as cellulose acetate, cellulose propionate, ethylcellulose, and ethyl chitin; silicate glass such as soda-lime glass, phosphate silicate glass, and borosilicate glass; and glass such as quartz glass. The materials for the inner container and the outer container may be used individually or in combination of two or more types.

[0063] The material of the inner container and the material of the outer container may be the same or different.

[0064] The material of the inner container is preferably a material with a specific gravity greater than that of the sample separation composition. The specific gravity of the inner container at 25°C is preferably greater than that of the sample separation composition at 25°C. In order to increase the specific gravity, the material of the inner container may contain components such as metal particles. Alternatively, weights such as metal particles may be placed in the inner container to increase its average specific gravity.

[0065] From the viewpoint of transparency and impact resistance, the material of the inner container is preferably a thermoplastic resin or glass, more preferably a thermoplastic resin, and even more preferably polyethylene terephthalate. The inner container is preferably a thermoplastic resin container or a glass container, more preferably a thermoplastic resin container, and even more preferably a polyethylene terephthalate container.

[0066] From the viewpoint of transparency and impact resistance, the material of the outer container is preferably a thermoplastic resin or glass, more preferably a thermoplastic resin, and even more preferably polyethylene terephthalate. The outer container is preferably a thermoplastic resin container or a glass container, more preferably a thermoplastic resin container, and even more preferably a polyethylene terephthalate container.

[0067] (Stopper) The sample collection container is equipped with a stopper. The stopper closes the open end of the outer container. The stopper seals the open end of the outer container. The stopper is attached to the open end of the outer container. The stopper is not in contact with the inner container. The stopper is not attached to the open end of the inner container. Preferably, the stopper is made of a material and has a shape that allows it to be attached to the open end of the outer container in an airtight and liquidtight manner.

[0068] The above-mentioned stopper body preferably includes a rubber stopper, and more preferably is a rubber stopper. If the above-mentioned stopper body includes a rubber stopper, the stopper body may include a stopper body which is a rubber stopper and a cap member made of plastic or the like.

[0069] Examples of materials for the rubber stopper mentioned above include isoprene rubber, isoprene-isobutylene rubber, butyl rubber, and halogenated butyl rubber.

[0070] (Composition for sample separation) The sample collection container comprises a composition for sample separation. The composition for sample separation is disposed between the outer surface of the inner container and the inner surface of the outer container.

[0071] The sample separation composition is in contact with the outer surface of the inner container. The sample separation composition is in contact with the inner surface of the outer container. Preferably, the sample separation composition is not in contact with the inner surface of the inner container.

[0072] Conventional known sample separation compositions can be used as the sample separation composition described above.

[0073] The above-mentioned sample separation composition is thixotropic. In this specification, "thixotropic" means the property of exhibiting fluidity when a shear force is applied, but losing fluidity when the shear force is removed.

[0074] The minimum yield value of the above-mentioned sample separation composition at 55°C is preferably 3 Pa or higher, preferably 100 Pa or lower, more preferably 75 Pa or lower, even more preferably 50 Pa or lower, and particularly preferably 30 Pa or lower. If the minimum yield value is above the lower limit, the leakage of the sample separation composition can be effectively suppressed even if the sample collection container is stored or transported in a tilted position under relatively high-temperature conditions. If the minimum yield value is below the upper limit, the workability of filling the sample separation composition during the manufacture of the sample collection container can be improved.

[0075] The minimum yield value of the above-mentioned sample separation composition at 55°C refers to the minimum Casson yield value obtained at shear rates from 10% to 90% in the torque range when the equilibrium viscosity of the above-mentioned sample separation composition at 55°C is measured using a cone-plate rotational viscometer (e.g., manufactured by Brookfield).

[0076] The specific gravity of the sample separation composition at 25°C can be appropriately changed depending on the sample being collected. The specific gravity of the sample separation composition at 25°C is preferably 1.025 or higher, more preferably 1.030 or higher, preferably 1.060 or lower, more preferably 1.050 or lower, even more preferably less than 1.050, and particularly preferably 1.040 or lower. When the specific gravity is above the lower limit and below the upper limit (or below the upper limit), the high-density component layer and the low-density component layer can be separated even more effectively. In particular, when the sample is blood, the plasma layer and the blood cell layer can be separated even more effectively, and the serum layer and the blood clot layer can be separated even more effectively.

[0077] The specific gravity of the above sample separation composition at 25°C is measured by sequentially adding one drop of the sample separation composition to 25°C saline solution, with the specific gravity adjusted in increments of 0.002, and observing its buoyancy. The specific gravity of the above saline solution at 25°C is measured using a hydrometer (for example, "DA-130N" manufactured by Kyoto Electronics Manufacturing Co., Ltd.).

[0078] The viscosity of the sample separation composition at 25°C and the viscosity of the sample separation composition at 55°C are not particularly limited. This is because the fluidity of the sample separation composition can be controlled by appropriately adjusting the distance between the outer surface of the inner container and the inner surface of the outer container, the difference in specific gravity between the inner container and the sample separation composition, and the centrifugation conditions.

[0079] The amount of the sample separation composition placed between the outer surface of the inner container and the inner surface of the outer container is not particularly limited, as long as at least a portion of the sample separation composition can flow into the inner container during the centrifugation operation in the centrifuge. The amount (volume) of the sample separation composition placed between the outer surface of the inner container and the inner surface of the outer container may be 1 mL or more, 10 mL or less, or 5 mL or less.

[0080] <Resin> The above sample separation composition preferably contains a resin. Examples of the resin include petroleum resins, cyclopentadiene resins, polyester resins, polyurethane resins, (meth)acrylic resins, silicone resins, α-olefin-fumarate copolymers, copolymers of sebacic acid, 2,2-dimethyl-1,3-propanediol, and 1,2-propanediol, polyether polyurethane resins, and polyether polyester resins. Only one of the resins may be used, or two or more may be used in combination.

[0081] The above resin preferably includes a petroleum-based resin, a cyclopentadiene-based resin, a polyester-based resin, or a (meth)acrylic-based resin, and more preferably includes a petroleum-based resin, a cyclopentadiene-based resin, or a (meth)acrylic-based resin. In this case, the fluidity of the above sample separation composition can be further increased, and the strength of the partition formed after the centrifugation operation can be further increased.

[0082] In 100% by weight of the above sample separation composition, the content of the above resin may be 40% by weight or more, 45% by weight or more, 75% by weight or less, or 60% by weight or less.

[0083] <Plasticizer> The above sample separation composition preferably contains a plasticizer. Examples of the plasticizer include benzene polycarboxylate alkyl ester derivatives. Only one type of plasticizer may be used, or two or more types may be used in combination.

[0084] The above plasticizer is preferably a benzenepolycarboxylate alkyl ester derivative.

[0085] Examples of the above-mentioned alkyl benzene polycarboxylate derivatives include phthalate esters, trimellitic acid esters, and pyromellitic acid esters. The above-mentioned alkyl benzene polycarboxylate derivatives may be used individually or in combination of two or more.

[0086] Examples of the trimellitic acid esters mentioned above include tri-n-octyl trimellitic acid, triisooctyl trimellitic acid, and triisodecyl trimellitic acid.

[0087] Examples of the pyromellitic acid esters mentioned above include tetraisooctyl pyromellitic acid.

[0088] The above-mentioned alkyl benzene polycarboxylate derivative is preferably a phthalate ester, trimellitic acid ester, or pyromellitic acid ester.

[0089] In 100% by weight of the above sample separation composition, the content of the plasticizer may be 20% by weight or more, 30% by weight or more, 60% by weight or less, or 50% by weight or less.

[0090] <Thixotropic-Imparting Components> The above sample separation composition preferably contains a thixotropic-imparting component. By using the above thixotropic-imparting component, a sample separation composition having thixotropic properties can be obtained. Examples of the above thixotropic-imparting component include inorganic fine powders and organic gelling agents. The above thixotropic-imparting component is preferably an inorganic fine powder or an organic gelling agent. The above thixotropic-imparting component may be used alone or in combination of two or more.

[0091] The thixotropy-imparting component described above preferably contains inorganic fine powder or an organic gelling agent. The sample separation composition described above preferably contains inorganic fine powder or an organic gelling agent.

[0092] Inorganic fine powder: The thixotropy-imparting component may or may not contain inorganic fine powder. The sample separation composition may or may not contain inorganic fine powder. Examples of the inorganic fine powder include fine silica powder, titanium oxide powder, calcium carbonate powder, zinc oxide powder, alumina powder, glass powder, talc powder, kaolin powder, bentonite powder, titania powder, smectite powder, and zirconium powder. Only one type of inorganic fine powder may be used, or two or more types may be used in combination.

[0093] The inorganic fine powders mentioned above are preferably fine silica powder, titanium oxide powder, calcium carbonate powder, zinc oxide powder, alumina powder, glass fine powder, talc powder, kaolin powder, bentonite powder, titania powder, smectite powder, or zirconium powder.

[0094] From the viewpoint of imparting even better thixotropy, the inorganic fine powder preferably contains hydrogen-bonding inorganic fine powder, more preferably contains hydrophilic silica, and even more preferably contains both hydrophilic silica and hydrophobic silica.

[0095] The average particle size of the inorganic fine powder is not particularly limited. The average particle size of the inorganic fine powder may be 1 nm or more, 10 nm or more, 50 μm or less, or 10 μm or less.

[0096] The average particle size of the inorganic fine powder described above is the average diameter measured on a volume basis (volume-average particle size), and is the value of the median diameter (D50) at which 50% of the particle size is determined. The volume-average particle size (D50) can be measured by laser diffraction / scattering, image analysis, Coulter method, and centrifugal sedimentation method, etc. It is preferable to determine the volume-average particle size (D50) by laser diffraction / scattering or image analysis.

[0097] In 100% by weight of the above sample separation composition, the content of the inorganic fine powder is preferably 0.1% by weight or more, more preferably 0.5% by weight or more, preferably 10% by weight or less, and more preferably 8% by weight or less. When the content of the inorganic fine powder is above the lower limit and below the upper limit, thixotropy can be further improved. In addition, the specific gravity of the sample separation composition can be appropriately increased.

[0098] Organic gelling agent: The thixotropy-imparting component preferably contains an organic gelling agent. The sample separation composition preferably contains an organic gelling agent. Examples of the organic gelling agent include amino acid derivatives, cyclic dipeptide derivatives, cyclohexane derivatives, benzenetricarboxylic acid derivatives, and sugar derivatives, and more specifically, dibenzylidenesorbitol, dibenzylidenesorbitol derivatives, and fatty acid amides. The organic gelling agent may be used alone or in combination of two or more.

[0099] The above organic gelling agent preferably includes a hydrogen-bonding organic gelling agent.

[0100] In 100% by weight of the above sample separation composition, the content of the above organic gelling agent is preferably 0.01% by weight or more, more preferably 0.05% by weight or more, preferably 1% by weight or less, and more preferably 0.5% by weight or less. When the content of the above organic gelling agent is above the lower limit and below the upper limit, thixotropy can be further improved.

[0101] <Other Components> The above-mentioned sample separation composition may contain other components besides those described above, as long as they do not impair the effects of the present invention. Examples of these other components include thermoplastic elastomers, auxiliary solvents, antioxidants, colorants, and water. Each of these other components may be used individually or in combination of two or more.

[0102] (Medicine) The sample collection container may contain a medicine. The medicine may be placed inside the inner container, inside the outer container, or both inside and outside the inner container. The form in which the medicine is contained is not particularly limited. The medicine may be placed on the inner surface of the inner container, or on the inner surface of the outer container. The medicine may adhere to the inner surface of the inner container, or adhere to the inner surface of the outer container. The medicine may be contained in granular form inside the inner container, or in granular form inside the outer container. The medicine may be contained in a liquid-dissolved state inside the inner container, or in a liquid-dissolved state inside the outer container. If there is a risk that the medicine or the sample separation composition may deteriorate due to contact between the medicine and the sample separation composition, the medicine may be placed only inside the inner container.

[0103] Examples of the above-mentioned drugs include anticoagulants, blood coagulation promoters, anticoagulants, and osmotic pressure regulators. Other examples of these drugs include inhibitors of various enzymes involved in glucose metabolism, fibrinolysis, nucleic acid degradation, or glycosylation.

[0104] Examples of the above-mentioned anticoagulants include heparin, metal salts of heparin, ethylenediaminetetraacetic acid (EDTA), metal salts of EDTA, and sodium citrate. These anticoagulants may be used individually or in combination of two or more.

[0105] Examples of the blood coagulation accelerators mentioned above include fine powders such as silica, diatomaceous earth, bentonite, and smectite; and enzymes such as thrombin and snake venom. Only one of these blood coagulation accelerators may be used, or two or more may be used in combination.

[0106] Examples of the blood clot prevention agents mentioned above include water-soluble polymers such as polyvinylpyrrolidone and polyvinyl alcohol; and nonionic surfactants such as polydimethylsiloxane-polyethylene glycol copolymer and polyethylene glycol-polypropylene glycol copolymer. The blood clot prevention agents may be used individually or in combination of two or more.

[0107] Examples of the osmotic pressure adjusting agents mentioned above include electrolytic hypertonic solutions.

[0108] Examples of the above inhibitors include protamine sulfate, a heparin neutralizer contained in dialysis samples; sodium fluoride, a glycolysis inhibitor; aprotinin, a fibrinolysis inhibitor; tetrachloride auric acid, a nucleolysis inhibitor; and oseltamivir phosphate, a glycosylation inhibitor. One of the above inhibitors may be used alone, or two or more may be used in combination.

[0109] When the above-mentioned sample collection container is used to separate blood into a plasma layer and a blood cell layer, it is preferable that the above-mentioned anticoagulant is contained in the inner container as the above-mentioned drug.

[0110] If the above-mentioned sample collection container is used to separate blood into a serum layer and a blood clot layer, the inner container may contain the above-mentioned drug, namely the blood coagulation accelerator.

[0111] If the above-mentioned sample collection container is used to separate blood into a serum layer and a blood clot layer, the inner container may contain the above-mentioned anti-clotting agent as the drug.

[0112] If the amount of sample collected in the sample collection container is insufficient to counteract the buoyancy that the inner container experiences when it is submerged in the sample separation composition, the inner container may contain weights such as metal granules.

[0113] (Further details of the sample collection container) The above sample collection container is used by setting it in a centrifuge after collecting the sample. The above sample collection container is used after centrifuging the sample after collection. The conditions for the centrifugal operation in the above centrifuge (centrifugal force, centrifugal time, and centrifugal temperature) can be found in the instruction manual (user manual), etc. The above sample collection container usually has specified conditions for the centrifugal operation in the above centrifuge.

[0114] In the sample collection container described above, during the centrifugation operation in the centrifuge, the inner container moves from the open end of the outer container toward the closed end of the outer container.

[0115] In the above-mentioned sample collection container, at least a portion of the sample separation composition flows into the inner container during the centrifugation operation in the above-mentioned centrifuge.

[0116] Samples are collected in the sample collection containers described above. Examples of such samples include bodily fluids such as blood and urine; plant biosap; seawater; freshwater such as lakes, rivers, groundwater, hot springs, and ice and snow; and aqueous suspensions collected from airborne components.

[0117] The internal pressure of the sample collection container is preferably less than 1 atm. The internal pressure of the sample collection container is preferably reduced. In this case, a predetermined amount of sample can be easily collected in the sample collection container. The internal pressure of the sample collection container may be 0.01 atm or higher, or 0.7 atm or lower.

[0118] The volume of the sample collected is not particularly limited. The volume of the sample collected may be 1 mL or more, or 8 mL or less. The volume of the sample collected can be controlled by the size of the inner container, the size of the outer container, and the internal pressure of the sample collection container.

[0119] The above sample is preferably blood. The above blood may contain an anticoagulant. The above sample collection container is preferably a blood collection container, and more preferably a vacuum blood collection tube. The above high specific gravity component layer is preferably a blood cell layer or a blood clot layer, and the above low specific gravity component layer is preferably a plasma layer or a serum layer.

[0120] If the above sample is blood, for example, extracellular components in the blood can be used as the substances to be tested. Examples of extracellular components in blood include proteins such as enzymes; glycolipids; sugars; electrolytes; low molecular weight peptides such as hormones; nucleic acids; vesicles, etc. These are extracellular components that may be affected by the metabolic activity of living cells or the breakdown of dead cells.

[0121] The above-mentioned sample collection container may be sterilized by radiation.

[0122] The above-mentioned sample collection container can be manufactured, for example, as follows.

[0123] The sample separation composition is placed in the outer container. The inner container is pushed into the sample separation composition in the outer container from the closed end side. By adjusting the length of the inner container's insertion, the contact area between the outer surface of the inner container and the sample separation composition can be adjusted. It is preferable to adjust the length of the inner container's insertion so that the sample collection composition does not protrude upward from the open end of the inner container. Next, the open end of the outer container is sealed with a stopper.

[0124] [Method for separating specimens] The method for separating specimens according to the present invention is a method for separating a specimen into a high-density component layer and a low-density component layer using the specimen collection container described above.

[0125] The method for separating a sample according to the present invention comprises the steps of (1) collecting a sample in the sample collection container and (2) setting the sample collection container containing the sample in a centrifuge and performing a centrifugation operation. Step (2) comprises the steps of (2A) moving the inner container from the open end side of the outer container toward the closed end side of the outer container, (2B) allowing at least a portion of the sample separation composition to flow into the inner container, and (2C) forming a partition wall separating a high-density component layer and a low-density component layer with the sample separation composition that has flowed into the inner container.

[0126] (Step (1)) In step (1), a sample is collected in the sample collection container. If the sample collection container is depressurized to a predetermined pressure, a predetermined amount of sample can be easily collected. If the sample is blood, for example, blood can be collected in the sample collection container using a blood collection needle.

[0127] (Step (2)) In step (2), the sample collection container obtained in step (1) (the sample collection container from which the sample was collected) is placed in a centrifuge and a centrifugation operation is performed. A conventionally known centrifuge can be used as the centrifuge. The type of centrifugal rotor is also not particularly limited. An angle rotor or a swing rotor may be used as the centrifugal rotor.

[0128] In step (2), the centrifugal force (centrifugal acceleration) at the position of the rotor's nominal rotation radius may be 300G or more, 800G or more, 1400G or more, 1800G or more, 4000G or less, 2500G or less, or 2000G or less.

[0129] The temperature (centrifugation temperature) in step (2) is set according to the recommended value depending on the purpose of the inspection. The temperature (centrifugation temperature) in step (2) may be 4°C or higher, 18°C ​​or higher, 25°C or higher, or 37°C or lower.

[0130] The centrifugation time in step (2) may be 5 minutes or more, 10 minutes or more, 20 minutes or more, or 60 minutes or less.

[0131] Step (2) comprises steps (2A), (2B), and (2C). Step (2A) may start immediately after the centrifugal separation operation has started, or it may start after a certain amount of time has elapsed since the centrifugal separation operation began.

[0132] In step (2A), the inner container moves from the open end of the outer container toward the closed end of the outer container. That is, in step (2A), the inner container moves from the top to the bottom. As a result of step (2A), the distance between the closed end of the inner container and the closed end of the outer container decreases, and consequently, the sample separation composition moves upward, and at least a portion of the sample separation composition flows into the inner container (step (2B)). The sample separation composition that has flowed into the inner container forms a partition between the low-density component layer and the high-density component layer (step (2C)). The partition is present in at least some part of the inner container. The low-density component layer and the inner container may or may not be in contact.

[0133] Specific embodiments of the present invention will be described below with reference to the drawings.

[0134] Figures 3(a) to 3(c) and 4(d) to 4(f) are cross-sectional views illustrating a method for separating a sample using the sample collection container shown in Figure 1.

[0135] Figure 3(a) shows the sample collection container 10 shown in Figure 1. First, a sample is collected in the sample collection container 10 (step (1)). In this embodiment, blood 9 is collected as the sample. Since the sample collection container 10 is under reduced pressure, a predetermined amount of blood 9 is collected according to the internal pressure. Figure 3(b) shows the sample collection container 10 after the blood 9 has been collected.

[0136] In this embodiment, the collected blood 9 coagulates in the sample collection container 10 and separates into serum 91 and blood clot 92 (Figure 3(c)).

[0137] Next, the sample collection container 10 is placed in a centrifuge and the centrifugation operation is performed (step (2)). As shown in Figures 4(d) and (e), during the centrifugation operation in the centrifuge, the inner container 1 moves from the open end 2a side of the outer container 2 toward the closed end 2b side of the outer container 2 (step (2A)). As the inner container 1 moves, the space between the inner container 1 and the outer container 2 narrows. Consequently, at least a portion of the sample separation composition 4 flows into the inner container 1 from the open end 1a (step (2B), Figure 4(e)). Figure 4(e) shows the blood clot 92 moving into the inner container 1 before the sample separation composition 4 flows into the inner container 1. Since the sample separation composition 4 is thixotropic, the sample separation composition 4 moves well during the centrifugation operation and flows into the inner container 1.

[0138] The sample separation composition 4 that flows into the inner container 1 forms a partition 41 between the serum layer 91A (low specific gravity component layer) and the blood clot layer 92A (high specific gravity component layer) (step (2C), Figure 4(f)). As shown in Figure 4(f), the volume of the inner container 1 is greater than the volume of the blood clot layer 92A (high specific gravity component layer).

[0139] The sample collection container after the completion of step (2) may be in the form shown in Figure 4(f), as well as in the form shown in Figure 5 or as shown in Figure 6. In Figures 5 and 6, reference numerals 10X and 10Y indicate the sample collection container after the completion of step (2) (after centrifugation). Reference numerals 1X and 1Y indicate the inner container, reference numerals 1Xa and 1Ya indicate the open end of the inner container, and reference numerals 1Xb and 1Yb indicate the closed end of the inner container. Reference numerals 2X and 2Y indicate the outer container, reference numerals 2Xa and 2Ya indicate the open end of the outer container, and reference numerals 2Xb and 2Yb indicate the closed end of the outer container. Reference numerals 3X and 3Y indicate the stopper. Reference numerals 4X and 4Y indicate the sample separation composition, and reference numerals 41X and 41Y indicate the partition formed by the sample separation composition. The labels 91X and 91Y represent low-density component layers, while the labels 92X and 92Y represent high-density component layers. In Figure 6, a relatively large amount of high-density component is present between the outer surface of the inner container and the inner surface of the outer container. By appropriately adjusting the lengths of the inner and outer containers, the volume of the sample separation composition, and the amount of sample collected, the state shown in Figure 5 or the state shown in Figure 6 can be achieved.

[0140] [Contents of the specimen collection container] The specimen collection container contents according to the present invention comprise a packaging member, the specimen collection container described above, and instructions for using the specimen collection container. In the specimen collection container contents according to the present invention, the specimen collection container is housed within the packaging member, and the instructions contain the conditions for centrifugal separation operation in a centrifugal separator, either written or recorded electronically.

[0141] Conventional packaging materials can be used as the above-mentioned packaging material. The above-mentioned packaging material may also be a packaging box.

[0142] The number of sample collection containers contained within the packaging material may be one, two or more, ten or more, fifty or more, seventy or more, 200 or less, or 150 or less.

[0143] The above instruction manual is preferably housed within the packaging material.

[0144] The above instruction manual contains the conditions for centrifugal separation operations in the centrifugal separator, either in written form or as electronic information. "Recorded as electronic information" means, for example, that the instruction manual includes a two-dimensional code such as a QR code (registered trademark), and that the conditions for the centrifugal separation operation can be recognized by reading this two-dimensional code.

[0145] The conditions for the above centrifugation operation include centrifugal force (centrifugal acceleration), temperature (centrifugal temperature), and centrifugation time. When centrifugation is performed in the above sample collection container under the conditions for the centrifugation operation described in the above instructions, the inner container moves from the open end side of the outer container toward the closed end side of the outer container. In addition, when centrifugation is performed in the above sample collection container under the conditions for the centrifugation operation described in the above instructions, at least a portion of the sample separation composition flows into the inner container.

[0146] It is preferable that the above instructions include a written description or electronic record of the type of sample to be collected (for example, that the sample is blood).

[0147] Preferably, the above instructions include the amount of sample to be collected (e.g., the volume of the sample) either in written form or recorded as electronic information.

[0148] The present invention will be described in more detail below with reference to examples. The present invention is not limited to the following examples.

[0149] The following materials were prepared for the sample separation composition.

[0150] (Resins) Petroleum-based resin 1 ("HB103" manufactured by ENEOS Material Co., Ltd.) Petroleum-based resin 2 ("SU500" manufactured by KOLON Corporation) Petroleum-based resin 3 ("SU100" manufactured by KOLON Corporation) Petroleum-based resin 4 ("SU90" manufactured by KOLON Corporation)

[0151] (Plasticizers) Plasticizer 1 (Kao Corporation's "T-08LP") Plasticizer 2 (J-PLUS Corporation's "DOTP")

[0152] (Thixotropy-imparting ingredients) Organic gelling agent ("GELALL-D" manufactured by Shin Nippon Rika Co., Ltd.) Hydrophilic silica (fine silica powder, "200CF" manufactured by Nippon Aerosil Co., Ltd.) Hydrophobic silica (fine silica powder, "R974" manufactured by Nippon Aerosil Co., Ltd.)

[0153] (Other) Thermoplastic elastomer ("SIS5229" manufactured by ENEOS Material Corporation)

[0154] Preparation of sample separation compositions I and II: In the proportions shown in Table 1, a plasticizer heated to 130°C to 140°C was dissolved with a petroleum-based resin, a thixotropy-imparting component (organic gelling agent), and a thermoplastic elastomer. Then, each component was mixed in a planetary mixer at 20°C to 30°C under reduced pressure to obtain sample separation compositions I and II.

[0155] Preparation of sample separation composition III: In the proportions shown in Table 1, a plasticizer heated to 130°C to 140°C was dissolved with a petroleum-based resin and a thixotropy-imparting component (organic gelling agent). Then, thixotropy-imparting components (hydrophilic silica and hydrophobic silica) were added. Next, each component was mixed in a planetary mixer at 20°C to 30°C under reduced pressure to obtain sample separation composition III.

[0156] For the obtained sample separation compositions I to III, the minimum specific gravity at 25°C and the minimum yield value at 55°C were determined using the method described above.

[0157] Table 1 below shows the composition, specific gravity at 25°C, and minimum yield value of sample separation compositions I to III.

[0158]

[0159] The following were prepared as the inner and outer containers.

[0160] (Inner container) Polyethylene terephthalate tube X (Length: 75 mm, Outer diameter of open end: 12.7 mm, Inner diameter of open end: 10.7 mm, Thickness: 1.0 mm, Volume: 6.5 mL) Polyethylene terephthalate tube Y (Length: 20 mm, Outer diameter of open end: 11.8 mm, Inner diameter of open end: 9.8 mm, Thickness: 1.0 mm, Volume: 1.3 mL)

[0161] (Outer container) Polyethylene terephthalate tube (Length: 100 mm, Outer diameter of open end: 15.7 mm, Inner diameter of open end: 13.3 mm, Thickness: 1.2 mm, Volume: 13.4 mL)

[0162] (Stopper) Rubber stopper

[0163] (Examples 1-4 and Comparative Examples 7, 8) 2.0 mL of the sample separation composition shown in Tables 2 and 4 below was placed in the bottom of the outer container. Next, the inner container (polyethylene terephthalate tube X) was pushed into the sample separation composition from the closed end. The pushing length of the inner container (polyethylene terephthalate tube X) was adjusted so that the area of ​​the portion in contact with the sample separation composition out of 100% of the outer surface area of ​​the inner container (polyethylene terephthalate tube X) was equal to the values ​​in Tables 2 and 4 below. Next, the open end of the outer container was sealed with a stopper while reducing the pressure to a degree that resulted in a blood collection volume of 6.2 mL (internal pressure of the sample collection container: 0.24 atm). In this way, a sample collection container (blood collection container) was obtained.

[0164] In the resulting sample collection container, the sample separation composition is in contact with the outer surface of the inner container and also in contact with the inner surface of the outer container. Furthermore, in the resulting sample collection container, the volume of the inner container is greater than the volume of the blood to be collected (6.2 mL). Furthermore, in the resulting sample collection container, the volume of the inner container is less than the sum of the volume of the sample separation composition (2.0 mL) and the volume of the blood to be collected (6.2 mL). In addition, in the resulting sample collection container, the shortest distance between the outer surface of the inner container and the inner surface of the outer container is 0.3 mm.

[0165] (Comparative Examples 1, 2, 5) 1.2 mL of the sample separation composition shown in Tables 3 and 4 below was placed in the bottom of the outer container. The outer container was depressurized to a degree that resulted in a blood collection volume of 4.0 mL, and the open end of the outer container was sealed with a stopper (internal pressure of the sample collection container: 0.67 atm). A sample collection container (blood collection container) was obtained in this way.

[0166] (Comparative Examples 3, 4, 6) 1.2 mL of the sample separation composition shown in Tables 3 and 4 below was placed in the bottom of the outer container. Next, the inner container (polyethylene terephthalate tube Y) was pushed into the sample separation composition from the closed end. The pushing length of the inner container (polyethylene terephthalate tube Y) was adjusted so that the area of ​​the portion in contact with the sample separation composition out of 100% of the outer surface area of ​​the inner container (polyethylene terephthalate tube Y) was equal to the values ​​in Tables 3 and 4 below. Next, the open end of the outer container was sealed with a stopper while reducing the pressure to a degree that resulted in a blood collection volume of 4.0 mL (internal pressure of the sample collection container: 0.65 atm). In this way, a sample collection container (blood collection container) was obtained.

[0167] In the resulting sample collection container, the sample separation composition is in contact with both the outer surface of the inner container and the inner surface of the outer container. Furthermore, in the resulting sample collection container, the volume of the inner container is smaller than the volume of the blood to be collected (4.0 mL). In addition, the shortest distance between the outer surface of the inner container and the inner surface of the outer container is 0.75 mm.

[0168] (Evaluation) (1) Amount of high-density components (blood cells) mixed into the septum 6.2 mL of Alsaver anticoagulant sheep blood (Ht.: approximately 40%) was collected in the inner container of the sample collection container obtained in Examples 1 to 4 and Comparative Examples 7 and 8. In addition, 4.0 mL of Alsaver anticoagulant sheep blood (Ht.: approximately 40%) was collected in the sample collection container obtained in Comparative Examples 1 to 6. Next, the sample collection containers were set in a centrifuge and centrifuged using a swing rotor at 25°C, 3420 G, and for 10 minutes.

[0169] In Examples 1-4 and Comparative Examples 7 and 8, during the centrifugation process, the inner container moved from the open end of the outer container towards the closed end, and at least a portion of the sample separation composition flowed into the inner container. Furthermore, the sample separation composition that flowed into the inner container formed a partition separating the high-density component layer (blood cell layer) from the low-density component layer (plasma layer). The sample collection container after centrifugation in Examples 1 and 2 had the configuration shown in Figure 6. The sample collection container after centrifugation in Examples 3 and 4 had the configuration shown in Figure 5.

[0170] In Comparative Examples 1, 2, and 5, the sample separation composition formed a partition separating the high-density component layer (blood cell layer) from the low-density component layer (plasma layer).

[0171] In Comparative Examples 3, 4, and 6, during the centrifugation operation, the inner container moved from the open end of the outer container towards the closed end of the outer container, but the sample separation composition did not flow into the inner container (the volume of the inner container was smaller than the volume of the high-density component layer). In Comparative Examples 3, 4, and 6, a partition wall was formed by the sample separation composition above the open end of the inner container, separating the high-density component layer (blood cell layer) from the low-density component layer (plasma layer). The sample collection containers after centrifugation in Comparative Examples 3, 4, and 6 had the form shown in Figure 7. In Figure 7, reference numeral 100A denotes the sample collection container after centrifugation. Reference numeral 100 denotes the inner container, reference numeral 200 denotes the outer container, reference numeral 400 denotes the sample separation composition, and reference numeral 410 denotes the partition wall formed by the sample separation composition. Reference numeral 910A denotes the low-density component layer (plasma layer), and reference numeral 920A denotes the high-density component layer (blood cell layer).

[0172] The septa were visually observed, and the amount of high-density components (blood cells) mixed into the septa was evaluated according to the following criteria. The greater the amount of blood cells mixed into the septa, the more the outer surface of the septum is colored red by the blood cells (red blood cells) mixed in.

[0173] <Criteria for determining the amount of high-density components (blood cells) mixed into the septum> A: The area of ​​the red-colored portion is 0% or more and less than 5% of the total area of ​​the outer surface of the septum B: The area of ​​the red-colored portion is 5% or more and less than 10% of the total area of ​​the outer surface of the septum C: The area of ​​the red-colored portion is 10% or more and less than 30% of the total area of ​​the outer surface of the septum D: The area of ​​the red-colored portion is 30% or more and less than 50% of the total area of ​​the outer surface of the septum E: The area of ​​the red-colored portion is 50% or more and less than 70% of the total area of ​​the outer surface of the septum F: The area of ​​the red-colored portion is 70% or more and 100% or less of the total area of ​​the outer surface of the septum

[0174] (2) Amount of deposit of high-density components (blood cells) on the upper surface of the septum The septum was visually observed, and the amount of deposit of high-density components (blood cells) on the upper surface of the septum was evaluated according to the following criteria.

[0175] <Criteria for determining the amount of high-density components (blood cells) deposited on the upper surface of the septum> A: Out of 100% of the upper surface area of ​​the septum, the area covered by blood cells is 0% or more and less than 5% B: Out of 100% of the upper surface area of ​​the septum, the area covered by blood cells is 5% or more and less than 10% C: Out of 100% of the upper surface area of ​​the septum, the area covered by blood cells is 10% or more and less than 30% D: Out of 100% of the upper surface area of ​​the septum, the area covered by blood cells is 30% or more and less than 50% E: Out of 100% of the upper surface area of ​​the septum, the area covered by blood cells is 50% or more and less than 70% F: Out of 100% of the upper surface area of ​​the septum, the area covered by blood cells is 70% or more and 100% or less

[0176] Figure 9 is an image diagram that visually illustrates the criteria for "(1) Amount of high-density components (blood cells) mixed into the septum" and "(2) Amount of high-density components (blood cells) deposited on the upper surface of the septum." In "(1) Amount of high-density components (blood cells) mixed into the septum," the squares filled in black in Figure 9 represent the areas colored red. In "(2) Amount of high-density components (blood cells) deposited on the upper surface of the septum," the squares filled in black in Figure 9 represent the areas covered by blood cells. For each criterion, the upper 100 squares represent an image diagram of the lower limit of the criterion, and the lower 100 squares represent an image diagram of the area near the upper limit of the criterion.

[0177] (3) Flow of the sample separation composition The sample collection container obtained was fixed in a position with the stopper side facing downwards at a 45-degree angle and placed in a 55°C oven. The sample collection container was observed 1 hour, 3 days, and 7 days after being placed in the 55°C oven. The distance over which the sample separation composition had flowed out due to the phase separation phenomenon was determined. In the table, "flowed out to the stopper" means that the flowed-out component reached the stopper.

[0178] The configuration and results are shown in Tables 2 to 4.

[0179]

[0180]

[0181]

[0182] In the sample collection containers obtained in Examples 1 to 4, the amount of blood cells mixed into the septum and the amount of blood cells accumulating on the upper surface of the septum were reduced. Furthermore, in the sample collection containers obtained in Examples 1 to 4, since the sample separation composition was placed between the outer surface of the inner container and the inner surface of the outer container, leakage was also suppressed.

[0183] 1, 1 A, 1 3,3X,3Y...Blug body 4,4X,4Y...Specimen separation composition 9...Blood 10,10X,10Y...Specimen collection container 41,41X,41Y...Partition wall 91...Serum 91A...Serum layer 91X,91Y...Low specific gravity component layer 92...Blood clot 92A...Blood clot layer 92X, 92Y...High specific gravity component layer R...Taper area

Claims

1. A sample collection container used by setting it in a centrifuge after collecting a sample, comprising: an inner container having an open end and a closed end; an outer container having an open end and a closed end; a stopper; and a thixotropic sample separation composition, wherein the inner container is positioned inside the outer container; the stopper closes the open end of the outer container; the inner container and the stopper are not in contact; the inner container and the outer container are not in contact; the sample separation composition is positioned between the outer surface of the inner container and the inner surface of the outer container; the sample separation composition is in contact with the outer surface of the inner container and the inner surface of the outer container; and the specific gravity of the sample separation composition at 25°C is 1.025 or more and less than 1.

050. A sample collection container wherein, during the centrifugal separation operation in the centrifugal separator, the inner container moves from the open end side of the outer container toward the closed end side of the outer container, and at least a portion of the sample separation composition flows into the inner container.

2. The sample collection container according to claim 1, wherein the volume of the inner container is smaller than the sum of the volume of the sample separation composition and the volume of the sample to be collected.

3. A specimen collection container according to claim 1 or 2, which is a blood collection container.

4. A method for separating a sample into a high-density component layer and a low-density component layer using a sample collection container according to any one of claims 1 to 3, comprising: (1) a step of collecting a sample in the sample collection container; (2) a step of setting the sample collection container from which the sample has been collected in a centrifuge and performing a centrifugation operation, wherein step (2) comprises: (2A) the inner container moving from the open end side of the outer container toward the closed end side of the outer container; (2B) at least a portion of the sample separation composition flowing into the inner container; and (2C) a partition wall separating the high-density component layer and the low-density component layer being formed by the sample separation composition that has flowed into the inner container.

5. The method for separating a specimen according to claim 4, wherein the specimen is blood.

6. A sample collection container comprising a packaging member, a sample collection container according to any one of claims 1 to 3, and instructions for using the sample collection container, wherein the sample collection container is housed within the packaging member, and the instructions contain the conditions for centrifugal separation operation in a centrifugal separator, either written or recorded electronically.

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