JPS6367659B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a serum separation method.

Conventionally, when separating a whole blood sample collected into a blood collection container, a so-called Spitz tube made of synthetic resin, into serum and blood clot, a separation layer-forming material having a specific gravity between these two, such as polystyrene small particles, silicone and silica, is used. A method has been proposed in which centrifugation is performed in the coexistence of a gel-like mixture of the above materials to form a separation layer made of the above materials between serum and blood clots, and the desired serum is collected by decantation or the like. However, when using a Spitz tube made of synthetic resin, blood coagulation takes a long time, and when using small polystyrene particles, the separation layer made of small polystyrene particles is easily destroyed by a slight impact. However, there was a drawback that caution was required when collecting serum from a Spitz tube by decantation. On the other hand, when using the above-mentioned gel-like mixture, since the gel-like mixture has thixotropic properties, there is a drawback that the operation when dispensing the gel-like mixture into a Spitz tube is difficult and the working efficiency is poor.

The present invention was made as a result of intensive research to eliminate the above-mentioned drawbacks, and it significantly promotes blood coagulation and forms a separation layer between serum and blood clots that is extremely stable against impact, etc. It is an object of the present invention to provide a new method for easily separating serum from blood with high yield.

The gist of the present invention is to provide a method for separating blood collected in a container into serum and blood clots by centrifugation. (2) 1 part by weight of fine particles having a ball tack value of 3 to 7 and having pressure-sensitive adhesive properties obtained by polymerizing an acrylic ester or methacrylic ester monomer alone or a monomer that can be copolymerized with these; The serum separation method is characterized in that a mixture consisting of 2 to 10 parts by weight of glass fine particles having a particle size of 50 to 500 microns coexists with blood in a container and then centrifuged.

The fine particles having pressure-sensitive adhesive properties in the present invention refer to fine particles having the property of adhesively bonding to each other when pressurized, and acrylic pressure-sensitive adhesive fine particles are used. The particle size of these fine particles having adhesive properties is preferably 0.1 to 5 mm, and it is preferable that the particle sizes are uniform. Further, the shape is not particularly limited, but a spherical shape is preferable. The specific gravity of the above-mentioned adhesive particles is set in the range of 1.03 to 1.08, which means that the specific gravity of the above-mentioned particles is 1.03 to 1.08.
If it is less than 1.03, the sticky particles will float in the serum phase, and if it exceeds 1.08, the sticky particles will settle in the blood clot phase, causing separation between the two layers. This is based on the reason that layers cannot be formed.

Incidentally, in order to adjust the specific gravity of the fine particles, an inorganic substance such as silica may be added to these sticky fine particles.

In the present invention, the adhesive fine particles can be produced by mixing an acrylic acid ester monomer such as 2-ethylhexyl acrylate or butyl acrylate alone or with a monomer that can be copolymerized therewith in the presence of an oil-soluble catalyst. If suspension polymerization is carried out in water below, fine particles having acrylic adhesive properties will be obtained. In addition, during the above polymerization, stabilizers include water-soluble polymers such as polyvinyl alcohol and polyacrylic acid, suitable surfactants, etc., and oil-soluble catalysts include peroxides such as benzoyl peroxide and methyl ethyl ketone peroxide. or azobisisobutyronitrile, etc. are used.

As the above-mentioned monomer, it is particularly preferable to use an acrylic ester or methacrylic ester of a primary or secondary alcohol having 4 to 10 carbon atoms. In addition, monomers that can be copolymerized with these monomers such as styrene, methyl methacrylate, acrylamide, acrylonitrile, etc. may be used in combination, and in particular, if polyfunctional monomers such as divinylbenzene and polyethylene glycol diacrylate are used in combination, a wide range of possibilities can be obtained. Fine particles can be obtained that can maintain a moderate degree of tackiness over a temperature range. After the adhesive fine particles synthesized in this way are thoroughly washed with water to completely remove residual impurities such as stabilizers,
It is important to use it dry.

As an index of the adhesiveness of the fine particles in the present invention, a ball tack value representing adhesive strength is used according to the method of J. Dow, which is commonly used in the field of adhesives. That is, fine particles having the tackiness to be measured are dispersed in an organic solvent such as ethanol, coated on a film substrate such as polyester, and dried.
This is fixed on a table with a slope of 30 degrees. Next, stainless steel balls of various sizes are rolled from the top of the table, starting from the largest ball, and the ball tack value is expressed as the size of the stainless steel ball that can stop in the adhesive-applied area with a length of 10 cm. For example, X/32
When the above conditions are satisfied using inch diameter stainless steel balls, the ball tack value is X.

The adhesive fine particles used in the present invention have a ball tack value of 3 to 7 at 25 DEG C. as measured by the above measuring method.

The glass fine particles in the present invention have a particle size of
Spherical shapes of 0.5mm or less are used, especially 50~
500μ is used. Usually, glass particles are used in an amount of 2 to 10 times the weight of the above-mentioned adhesive particles. Further, it is preferable to mix the adhesive particles so that their surfaces are covered with glass particles and the glass particles are continuously dispersed.

The mixture of sticky particles and glass particles obtained as described above is placed in the bottom of a Spitz tube, then the collected blood is added, and after the blood has coagulated, the mixture is centrifuged. The serum is separated from the sticky particles and settles at the bottom of the tube, and a separation layer consisting of the sticky particles is formed between the serum and the blood clot. Note that a mixture of adhesive particles and glass particles may be added after blood is poured into the Spitz tube.

The serum separation method of the present invention is configured as described above, and since centrifugation is carried out by coexisting pressure-sensitive adhesive particles and glass particles, blood collected in a container, particularly a Spitz tube made of synthetic resin, is collected. The coagulation of serum and blood clots is significantly promoted and blood coagulation occurs in a short period of time, and after centrifugation, fine particles with pressure-sensitive adhesiveness bond to each other between serum and blood clots, resulting in separation that will not be destroyed by impact, etc. Since a layer is formed, serum can be collected in good yield by simple operations such as decantation. The present invention will be explained below using examples.

Example 1 200 parts by weight of ion-exchanged water, 0.5 parts by weight of polyvinyl alcohol (degree of polymerization 1500), 80 parts by weight of butyl acrylate, 15 parts by weight of styrene, 5 parts by weight of divinylbenzene, and 0.3 parts by weight of benzoyl peroxide were charged into a reaction vessel. The mixture was reacted at 80°C in a nitrogen stream for 10 hours to prepare an aqueous dispersion of sticky fine particles. Fine particles were separated from this dispersion, washed several times with ion-exchanged water to remove polyvinyl alcohol, and then freeze-dried at -50°C to obtain sticky fine particles. The particle size of this fine particle is 0.1~0.5mm
The ball tack value was 4.

To 1 part by weight of this sticky fine particles, 3 parts by weight of glass fine particles with a particle size of 50 to 100μ are added,
After mixing so that the glass particles surrounded the sticky particles, 3 g of this mixture was placed at the bottom of a polystyrene Spitz tube, and then the collected blood was added. Approximately 40 minutes later, blood coagulation progressed and the blood clot separated from the serum, so when centrifuged at 3000 rpm for 5 minutes, the glass particles remained at the bottom of the spittoon, and the sticky particles separated from the serum and blood clot. The fine particles bonded to each other in between to form a separation layer.
This separation layer was not destroyed even by decantation, and serum could be easily collected from the Spitz tube.

Example 2 200 parts by weight of ion-exchanged water, 0.5 parts by weight of particle polyvinyl alcohol (degree of polymerization 1500), 70 parts by weight of 2-ethylhexyl acrylate, 20 parts by weight of methyl methacrylate, 10 parts by weight of ethylene glycol dimethacrylate, and 0.3 parts by weight of benzoyl peroxide. was charged into a reaction container and reacted in the same manner as in Example 1, separated, washed with water, and freeze-dried at -50°C to obtain particles with a particle size of 1.
Microparticles with a stickiness of ~2 mm were obtained.

The ball tack value of this fine particle was 4. For 1 part by weight of this sticky fine particle, the particle size is 50
After adding 3 parts by weight of glass particles of ~100 μm and mixing so that the glass particles surrounded the sticky particles, 3 g of this mixture was placed at the bottom of a polystyrene Spitz tube, and then the collected blood was added. After about 40 minutes, blood coagulation progressed and the blood clot was separated from the serum, so when centrifuged at 3000 rpm for 5 minutes, the glass particles remained at the bottom of the spittoon, and the sticky particles separated between the serum and blood clot. These fine particles bonded together to form a separation layer. This separation layer was not destroyed even by decantation, and serum could be easily collected from the Spitz tube.

Claims (1)

[Claims] 1 In the method of separating blood collected in a container into serum and blood clots by centrifugation, (1)
1.03 to 1.08, the particle size is 0.1 to 5 mm, the ball tack value at 25°C is 3 to 7, and it is obtained by polymerizing an acrylic ester or methacrylic ester monomer alone or a monomer that can be copolymerized with these. , characterized in that a mixture consisting of 1 part by weight of fine particles having pressure-sensitive adhesive properties and (2) 2 to 10 parts by weight of glass fine particles with a particle size of 50 to 500 μ coexists with blood in a container and then centrifuged. Serum separation method.