JPS64660B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a separation composition used when subjecting a blood sample to centrifugation to separate its liquid components, serum or plasma, from solid components mainly composed of red blood cells. In recent years, testing of blood components in clinical laboratory departments has become extremely important, and the number of tests conducted has continued to increase. Among these, many biochemical tests use only serum or plasma as a sample, and it is necessary to separate serum or plasma from solid components as a preliminary operation for testing. For this reason, conventionally, serum or plasma has been collected by precipitating the blood cell portion by centrifugation and then sucking it up with a pipette. However, this method provides insufficient separation and is very time-consuming.Recently, various methods have been devised to perform this preparative separation operation easily and with high yield. One method is to add a substance having a specific gravity intermediate between that of serum or plasma and the solid component into a blood sample, and use centrifugal separation to position the substance between the two to form a partition wall. According to this method, it is possible to separate serum or plasma only by decantation, and it is possible to reduce time and labor, but on the other hand, it also has the following disadvantages. That is, three types of materials have been proposed so far: a solid form, a liquid form, and a mixture thereof. Solid forms include, for example, polystyrene powder or pellet materials, but when these are used, their function as a barrier is insufficient, so blood cells may not be mixed into serum or plasma. It has various drawbacks, such as the fact that the partition wall itself is easily destroyed. Also, acrylic polymers are known as liquid polymers, but in general, when trying to obtain a high viscosity liquid polymer from monomers such as acrylic polymers, it is necessary to control the reaction. Depending on the reaction method, there are many difficult manufacturing problems such as removal of impurities.
Moreover, because liquid forms have fluidity, they also have the disadvantage of being troublesome to transport and store before use. Furthermore, as mixtures of solid and liquid, thixotropic compositions such as silicone with silica powder added and modified liquid polybutadiene with alumina are known, but these generally deteriorate over time. The disadvantage is that the viscosity increases or decreases as the temperature increases. That is, if the viscosity increases, strong centrifugal force must be applied for a long time to move the composition to a position intermediate between serum or plasma and blood cells for centrifugation after long-term storage. In some cases, the composition does not flow even when a normal centrifugal force obtained in the laboratory is applied, so that no septum is formed.On the other hand, if the viscosity decreases over time, it is placed in a blood collection tube.
Initially, the serum portion was separated from the blood cell portion by a partition wall stably formed by centrifugation, but when the blood collection tube is tilted to pour it out, the partition wall tends to collapse, resulting in incomplete separation of the serum portion and blood cell portion. It was hot. As a result of extensive research in view of the current state of compositions for serum or plasma separation as described above, the present inventors have found that two types of viscous liquids have different interactions between a thixotropic agent and the thixotropic agent. The researchers discovered that a composition that does not change in viscosity over time can be obtained by combining the two, and based on this knowledge, a stable barrier is easily formed under normal centrifugation conditions, and serum or plasma The present invention has completed a serum or plasma separation composition that can be easily and accurately separated and does not require any special measures for transportation or storage. Therefore, the gist of the present invention is (1) an average particle diameter of 1 mμ;
1 part by weight of a thixotropic agent selected from ~100μ silica powder or acrylic resin powder, (2) Strong interaction with the thixotropic agent selected from the group consisting of epoxidized animal and vegetable oils, acrylic resin oligomers, and liquid acrylic resins. and (3) a viscous liquid A selected from liquid chlorinated polybutene or epoxidized liquid 1,2-polybutadiene and having no strong interaction with the thixotropic agent A viscous liquid B having good compatibility is a mixture of three components of 0.1 to 20 parts by weight, and the ratio of viscous liquid A to viscous liquid B is 100 parts by weight to 10 to 2000 parts by weight. ,20℃
A composition for separating serum or plasma characterized by having a specific gravity of 1.03 to 1.08. As the thixotropy-imparting agent in the present invention, silica powder or acrylic resin powder, and surface-treated products thereof that have been subjected to hydrophilic treatment or hydrophobic treatment by grafting reaction or coupling reaction, etc. are used. These thixotropic agents used have an average particle size of 1 mμ to 100μ.
If it is smaller than 1 mμ, it is difficult to handle, and when mixed with the viscous liquid described below, it tends to aggregate and form secondary particles, making uniform dispersion difficult.
This is because if it is larger than this, the dispersion stability in the viscous liquid will be poor, and the separation composition as a whole will lack uniform fluidity. In the present invention, having a strong interaction with a thixotropic agent means that after a certain thixotropic agent is mixed with a certain viscous liquid and uniformly dispersed, a centrifugal separator with an arm length of 10 cm is used at a rotation speed of 4000 r.pm.
This refers to a case in which no bias is observed in the distribution of the components of the mixture even after centrifugation for 30 minutes. In addition, "not having a strong interaction with the thixotropic agent" refers to a case where the distribution of the components of the mixture is found to be uneven after centrifugation. The cause of such interaction is not yet clear, but between materials with hydrophilic groups it is mainly due to hydrogen bonding, and between materials without hydrophilic groups it is due to cohesive force caused by the molecular structure. It is assumed that this is the case. In the present invention, when the thixotropic agent is silica powder, the viscous liquid A includes epoxidized animal and vegetable oils such as soybean oil, linseed oil, safflower oil, and fish oil, and the thixotropic agent is acrylic resin. In the case of powder, the viscous liquid A is an acrylic resin oligomer or liquid acrylic resin, and both have a viscosity of 1000 cps.
The above is preferable. In the present invention, viscous liquid material A and viscous liquid material B have good compatibility means that certain liquid materials A and B
This refers to the case where phase separation does not occur even after being mixed and uniformly dispersed and left at room temperature for one week. Liquid chlorinated polybutene is used as the viscous liquid B having good compatibility with the viscous liquid A used when the thixotropic agent is silica powder, and when the thixotropic agent is acrylic resin powder. Epoxidized liquid 1,2-polybutadiene is used, preferably having a viscosity of 1000 cps or more. When selecting specific materials for the three components of the thixotropic agent, viscous liquid A, and viscous liquid B in the present invention, the three components should be selected at the same time. Each component may be formed from two or more types of substances as long as interaction and compatibility are satisfied. Further, appropriate additives such as colorants may be added. The quantitative relationship of the three components described above varies depending on the average particle size of the thixotropy imparting agent, the viscosity of the viscous liquids A and B, etc., but in terms of weight ratio, 1 part by weight of the thixotropy imparting agent to the viscous liquids A and B 0.1 to 20 parts by weight each are used. If the amount of the thixotropy imparting agent is too large, fluidity will be poor, and if it is too small, sufficient thixotropy will not be obtained. In addition, the mixing ratio of viscous liquids A and B is set within a suitable range taking into account the strength of interaction with each thixotropic agent, but generally liquid B is mixed to 100 parts by weight of liquid A. is used in an amount of 10 to 2000 parts by weight.
However, in order for the mixture of the three components mentioned above to achieve the intended purpose, the specific gravity at 20°C must be 1.03 to 1.08. In the present invention, there is no restriction on the order in which the components are mixed, and the three components may be mixed at the same time, or in the case of mixing in two stages, two components are mixed first and then the third component is mixed. or vice versa, but generally a thixotropic agent is added to the mixture of liquids A and B. In order to separate serum or plasma from blood cells using the separation composition of the present invention, it is sufficient to add the separation composition to sample blood and perform a centrifugation operation. Since a barrier wall is formed by the composition of the present invention at the interface with the blood serum or plasma, serum or plasma can be easily and precisely removed by decantation or the like. The serum or plasma separation composition of the present invention comprises (1) 1 part by weight of a thixotropic agent selected from silica powder or acrylic resin powder with an average particle size of 1 mμ to 100 μm, (2) epoxidized animal or vegetable oil, acrylic resin oligomer, and 0.1 to 20 parts by weight of a viscous liquid A selected from the group consisting of liquid acrylic resins and having a strong interaction with the thixotropic agent; and (3) liquid chlorinated polybutene or epoxidized liquid 1,2-polybutadiene. , a mixture of 0.1 to 20 parts by weight of a viscous liquid B having no strong interaction with the thixotropic agent and having good compatibility with the viscous liquid A; Since the ratio of viscous liquid B is 100 parts by weight to 10 to 2000 parts by weight, and the specific gravity at 20°C is 1.03 to 1.08, it has suitable thixotropic properties as a separation composition, and the viscosity does not increase over time. Therefore, even when used immediately after manufacture or after long-term storage, a septum is easily formed in the blood collection tube under normal centrifugation conditions without the need for a particularly strong centrifugal force, allowing serum or plasma to be easily and accurately removed. In addition, because the viscosity does not decrease over time, the septum is stably formed even after long-term storage, and once the septum is formed, even after a long period of time, it is easy to maintain the septum by tilting the blood collection tube. It will not collapse. Examples of the present invention will be described below. Example 1 Average particle size 10m as thixotropic agent
μ, silica powder with specific gravity 2.2 at 20℃, specific gravity 1.03 at 20℃ as viscous liquid A, viscosity
Epoxidized linseed oil of 1500 cps and liquid chlorinated polybutene having a specific gravity of 0.95 at 20°C and a viscosity of 8000 cps as viscous liquid B were prepared. Next, prepare three kinds of mixtures of each of these two components in the proportions shown in Table 1, put mixtures A and B into a glass Spitz tube, and heat at 4000 rpm for 30 minutes with an arm length of 10.
Immediately after centrifugation was carried out under conditions of 1 cm, the state of the mixture was observed by holding the tube vertically.

[Table] The silica in mixture A was uniformly dispersed in the epoxidized linseed oil, but the silica in mixture B was unevenly distributed below the liquid chlorinated polybutene. on the other hand,
When the mixture was placed in a Spitz tube and allowed to stand at room temperature for one week, the epoxidized linseed oil and liquid chlorinated polybutene remained uniformly dissolved in each other, with no phase separation occurring. Furthermore, these silica powder, epoxidized linseed oil,
Liquid chlorinated polybutene in this order at a weight ratio of 1:
First, epoxidized linseed oil and liquid chlorinated polybutene were mixed and stirred in a vacuum container at 50°C, then silica powder was added and dispersed uniformly, and the mixture was heated to 20°C. Cooled specific gravity 1.05
A composition for separation was obtained. Thereafter, 1 g of the composition was injected into four glass Spitz tubes each having a capacity of 10 ml. Immediately after production, sample blood was added to one of these bottles and heated at 2000 rpm for 3 minutes.
When centrifuged at an arm length of 10 cm, the composition formed a partition between the serum and the blood clot, and the serum could be easily separated by decantation. Also, another Spitz tube was inverted and tilted at an angle of about 60° with respect to the horizontal plane, but the composition did not flow. Furthermore, the remaining two Spitz tubes were left at room temperature and after one month, the same test as above was conducted, but there was no increase or decrease in the viscosity of the composition, and the test results were the same as in the above case. . Furthermore, even though the Spitz tube in which the septum had been formed by centrifugation immediately after the composition was prepared was tilted again, the septum did not collapse. Comparative Example The same silica powder, epoxidized linseed oil, and liquid chlorinated polybutene as used in Example 1 were prepared, and 1 part by weight of silica powder was added to 15 parts by weight of epoxidized linseed oil, and the mixture was heated and stirred. A specific gravity of 1.06) at 20°C was obtained. Further, 1 part by weight of silica powder was added to 6 parts by weight of liquid chlorinated polybutene to obtain a mixture B (specific gravity 1.04 at 20°C) in the same manner as above. When sample blood was added to mixture A in a Spitz tube and centrifuged under the same conditions as in Example 1, a septum was formed at an intermediate position in the whole blood immediately after preparation of mixture A, but After one month, the viscosity became so high that the composition did not move at all and no partition walls were formed. When the same inversion test as in Example 1 was performed on mixture RO, it was observed that mixture RO was slowly flowing downward both immediately after production and one month later. Example 2 As a thixotropic agent, a suspension polymer of triethylene glycol dimethacrylate (average particle size 50μ, specific gravity 1.13 at 20°C), viscous liquid A
Liquid polybutyl methacrylate (specific gravity 1.06 at 20°C, viscosity 80,000 cps) was prepared as the viscous liquid B, and epoxidized liquid 1,2-polybutadiene (specific gravity 0.97 at 20°C, viscosity 200,000 cps) was prepared as the viscous liquid B. Similarly to Example 1, liquid polybutyl methacrylate has a strong interaction with a polymer of triethylene glycol metal acrylate, and epoxidized liquid 1,2-polybutadiene has a strong interaction with a polymer of triethylene glycol dimethacrylate. It was confirmed that there was no interaction but good compatibility with liquid polybutyl methacrylate. These triethylene glycol dimethacrylate polymer, liquid polybutyl methacrylate, and epoxidized liquid 1,2-polybutadiene were weighed in this order so that the weight ratio was 3:4:3 and placed in a vacuum container.
Stir and mix at 60°C, then cool to determine the specific gravity at 20°C.
A composition of 1.05 was obtained. Next, this composition was subjected to centrifugal separation and an inversion test under the same conditions as in Example 1, and its condition was observed. As a result, there was no sign of the composition dripping either immediately after mixing the composition or after one month when the composition was left standing upside down. When centrifuged at 2000 rpm for 3 minutes together with sample blood, the composition showed good fluidity both immediately after mixing and after 1 month, forming a stable barrier between serum and blood clot. The serum could then be easily fractionated.

Claims (1)

[Claims] 1 (1) 1 part by weight of a thixotropic agent selected from silica powder or acrylic resin powder with an average particle size of 1 μm to 100 μm; (2) 1 part by weight of a thixotropic agent selected from the group consisting of epoxidized animal and vegetable oils, acrylic resin oligomers, and liquid acrylic resins; 0.1 to 20 parts by weight of a viscous liquid A that has a strong interaction with a thixotropic agent and (3) a liquid chlorinated polybutene or an epoxidized liquid 1,2-polybutadiene, which has a strong interaction with a thixotropic agent. Viscous liquid B0.1-20 that has good compatibility with viscous liquid A
Three parts by weight are mixed, and the ratio of viscous liquid A to viscous liquid B is 100 parts by weight to 10 to 10.
2000 parts by weight, specific gravity at 20℃ is 1.03~
A composition for serum or plasma separation, characterized in that the molecular weight is 1.08.