JPS629861B2 - - Google Patents

Description

[Detailed description of the invention]

[Background of the Invention] Technical Field The present invention relates to a blood collection tube containing a separation composition used when centrifuging blood into serum or plasma and other components by utilizing the difference in specific gravity of each component. Prior Art Conventionally, whole blood collected in a blood collection test tube for blood testing has been centrifuged to separate serum or plasma from blood cells, etc., and this has been analyzed, or transported or stored for analysis. It can be done. In this case, in order to reliably separate serum or plasma, it is known to use a separation composition, usually called a barrier, which has a specific gravity intermediate to that of the phase to be separated. For example, Japanese Patent Application Publication No. 49-89389 or U.S. Patent No.
No. 3,780,935 discloses the use of a gel-like material consisting of a mixture of silicone fluid and hydrophobic silicon dioxide as a separation composition of this type. This gel-like material exhibits fluidity and moves between the phases to be separated due to the stress during centrifugation, and at the end of centrifugation, a stable separation layer that will not be easily destroyed is formed between the separated phases. Ru. Problems with the prior art However, gel materials made of a combination of silicone fluid and silica particles, for example,
83654, the silicone fluid reacts with the silica particle surface, its viscosity decreases over time, and the serum portion is collected from the phase-separated test tube by tilting the tube, which disturbs the barrier layer. Components of the blood cell phase may diffuse into serum components, which may adversely affect the accuracy of serum analysis. This is unfavorable in terms of storage of phase-separated blood collection test tubes. Furthermore, since this type of separation composition contains silicone fluid as its main component, the rate of blood coagulation is slow, and in order to shorten testing time, it requires secondary treatment to promote blood coagulation or centrifugation. At the same time, a large stress of at least 1100 G is required, which is an excessive burden and may cause hemolysis. In addition, there are various drawbacks, such as the necessity of using an expensive centrifugal separator that can rotate at high speed. [Object of the Invention] This invention has been made in view of the above circumstances, and has thixotropic properties, easily exhibits fluidity during centrifugation of liquid, moves to the middle of the separated phase, and at the end of centrifugation, Contains a composition for serum or plasma separation that maintains a stable gel-like state that is not easily destroyed, has little effect of viscosity change during long-term storage in air or vacuum, and is preferable for promoting blood coagulation. The object of the present invention is to provide a blood collection tube that is maintained in a reduced pressure state by a stopper. The product that achieves the above purpose consists mainly of a liquid polybutadiene modified product that has been subjected to a modification treatment to prevent gelation in a bottomed tube with an opening, and an appropriate amount of a specific gravity and viscosity modifier and a thixotropic agent to impart thixotropy. containing a composition for separating serum or plasma from blood which is maintained at a substantially constant viscosity in vacuum by adding a structure-forming agent, and the opening of the bottomed tube is closed with a stopper. It is a sealed vacuum blood collection tube. Furthermore, it is preferable that the bottomed tube has the opening on the opposite side of the bottom. Furthermore, it is preferable that the liquid polybutadiene modified product is epoxidized polybutadiene or maleated polybutadiene, and has a specific gravity in the range of 1.035 to 1.065. Furthermore, it is preferable that the specific gravity and viscosity modifier is a fine inorganic powder selected from fine silica, alumina, and carbon black, and a fine powder selected from fine plastic powder, either alone or in combination. Furthermore, it is preferable that the structure forming agent is at least one selected from 1,3-trimethylene glycol, 1,4-butanediol, 1,5-pentadiol, diethylene glycol, and a silane coupling agent. Furthermore, the separation composition comprises 100 parts by weight of a liquid polybutadiene modified material, 5 to 10 parts by weight of finely powdered silica as a specific gravity and viscosity modifier, and 0.1 to 2.0 parts by weight of trimethylene glycol as a structure forming agent, and has a specific gravity of
It is preferably in the range of 1.035 to 1.065. [Specific Description of the Invention] The present invention will be described below with reference to illustrated embodiments. The drawing shows an embodiment of the blood collection tube according to the present invention, in which the bottom of the bottomed tube body 1 (10 c.c. tube) has a depth of approximately 15 mm.
A serum or plasma separation composition 2 is contained in the tube 1, and a stopper 3 made of, for example, butyl rubber is fitted into the opening of the bottomed tube 1. In this case, the bottomed tube body 1
The interior is kept in a vacuum state, that is, under reduced pressure, to facilitate drainage during blood collection. Furthermore, the shapes of the bottomed tube body 1 and the plug body can be arbitrarily selected from known shapes. Moreover, the tube body 1 of the separation composition 2
The storage position within the tube is not limited to the bottom of the tube, but as is well known, it may be held at the upper part of the tube or at an intermediate position as required. The composition for serum or plasma separation used in this invention is characterized by being subjected to gel-preventing treatment such as epoxidation or maleation from the viewpoint of long-term storage. As specific gravity and viscosity modifiers, inorganic fine powders such as finely divided silica, alumina, and carbon black, or fine plastic powders such as fine nylon powders can be used alone or in combination. The specific gravity and viscosity modifier may be appropriately selected from those that have good dispersibility in the liquid modified polybutadiene and do not have any adverse effect on the liquid to be centrifuged. Structure-forming agents for imparting thixotropy include 1,3-trimethylene glycol, 1,4-
butanediol, 1,5-pentanediol, diethylene glycol, silane coupling agents such as alkoxysilanes such as glycidoxy-propyltrimethoxysilane. In the present invention, the composition for serum or plasma separation is usually adjusted to have a specific gravity in the range of 1.035 to 1.065. A composition example in this case is shown below.

[Table] In this invention, the composition for serum or plasma separation is stored in a vacuum, and if necessary, an appropriate amount is dispensed into a bottomed tube in advance, and then defoamed by a vacuuming step. The tube is then sealed with a stopper and used as a vacuum blood collection tube. Example 100 parts by weight of epoxidized cis-butadiene (specific gravity d ₂₄ 1.019, viscosity 4500CP/20°C), 5.5 parts by weight of Aerosil (trade name, hydrophobic silica fine powder specific gravity 2.2 manufactured by Nippon Aerosil Co., Ltd.), and 0.2 parts by weight of trimethylene glycol
Mix parts by weight, specific gravity approximately 1.048, viscosity approximately 1.5 million
A thixotropic substance of CP (20°C) was obtained. This was then stored in air or vacuum, and as a comparative example, a similar thixotropic substance was stored in air and its viscosity change was measured in the same manner. The results were as shown below.

[Table] From Table 2, it was found that the viscosity of thixotropic substances increases in air, contrary to the prior art, and that almost no viscosity change occurs in vacuum. Next, add 2 c.c. of this composition to a container with a diameter of 12 mm and a volume of 10
The sample was dispensed into a cc blood collection test tube, which was then vacuumed, that is, kept under reduced pressure, and sealed with a stopper to allow for drainage during blood collection.The blood was then collected using this test tube. . This is centrifuged (2500r.pm)
, for 10 minutes, arm length approximately 10 cm), and as a result, in the example of the present invention, a disc-shaped barrier layer with a thickness of approximately 2 cm was formed between the serum and blood cells. It was confirmed that this barrier layer was not destroyed at all even when left for several tens of days or when subjected to shocks such as vibrations, and could maintain a stable non-fluid state. In this example, maleated cis-polybutadiene (specific gravity d ₂₄ 1.016, viscosity 4500CP/20
As a result of carrying out the same procedure except that epoxidized cis-butadiene was used, almost the same results were obtained as when using epoxidized cis-butadiene. As detailed above, since this composition for serum or plasma separation has stable thixotropic properties by being stored in vacuum in advance, the barrier layer formed by centrifugation is easily destroyed. Since the separated layer can be easily separated by decantation, the yield can be increased in serum separation, etc., and the viscosity does not change even in vacuum, making it possible to store the separated layer for a long time. It is possible. Furthermore, since the thixotropic index is relatively large, the stress during centrifugation of about 700 G is sufficient, so there is no risk of destruction of blood cells, etc., making it extremely advantageous in use.

[Brief explanation of the drawing]

The drawing is a sectional view showing one embodiment of a blood collection tube according to the present invention. 1... Bottomed tube body, 2... Serum or plasma separation composition, 3... Stopper body.

Claims (1)

[Scope of Claims] 1 A bottomed tube having an opening contains a liquid polybutadiene modified product which has been subjected to a modification treatment to prevent gelation as a main component, and contains an appropriate amount of a specific gravity and viscosity modifier and a thixotropic property. Contains a composition for separating serum or plasma from blood that is maintained at a substantially constant viscosity in vacuum by adding a structure-forming agent, and seals the opening of the bottomed tube body with a stopper. A vacuum blood collection tube characterized by: 2. The blood collection tube according to claim 1, wherein the bottomed tube has the opening on the opposite side of the bottom. 3. The blood collection tube according to claim 1 or 2, wherein the liquid polybutadiene modified product is epoxidized polybutadiene or maleated polybutadiene, and has a specific gravity in the range of 1.035 to 1.065. 4. The blood collection tube according to claim 3, wherein the specific gravity and viscosity modifier is a fine inorganic powder selected from fine silica, alumina, and carbon black, and a fine powder selected from fine plastic powder, either alone or in combination. . 5. Claim 3, wherein the structure forming agent is at least one selected from 1,3-trimethylene glycol, 1,4-butanediol, 1,5-pentadiol, diethylene glycol, and a silane coupling agent. Blood collection tube as described. 6 The separation composition consists of 100 parts by weight of a liquid polybutadiene modified material, 5 to 10 parts by weight of finely powdered silica as a specific gravity and viscosity modifier, and 0.1 to 2.0 parts by weight of trimethylene glycol as a structure forming agent, and has a specific gravity of 1.035. 2. The blood collection tube according to claim 1 or 2, wherein the blood collection tube is in the range of 1.065 to 1.065.