JPS5837560A - Sealant for separation of serum or plasma - Google Patents

Abstract

PURPOSE:To separate easily and effectively a serum or plasma from blood corpuscles without contamination, by using a sealant consisting of a thixotropic gelatinous material obtained by dispersing an organic gelling agent and inorganic fine powder in a fluid acrylic resin. CONSTITUTION:The titled sealant for separation of a serum or plasma is characterized by dispersing an organic gelling agent, and additionally an inorganic fine powder according to the need, in a fluid acrylic resin to form a thixotropic gelatinous material, moreover allowing the density to be 1.03-1.08, the viscosity 1,500-7,000ps at 25 deg.C. The main component fluid acrylic resin is consisting of a polymer obtained by polymerization of >=1 functional or nonfunctional alkyl acrylate or alkyl methacrylate as a polymerizable monomer. As the organic gelling agent, for exapmle, ''Gelol '' is used, and as the inorganic fine powder used for a density modifying additive, materials of high density and inactivity such as silicon dioxide, alumina, titanium dioxide, calcium carbonate are preferable.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealant for separating serum or plasma, and its purpose is to separate a blood sample into a serum or plasma portion and a blood cell portion by means such as centrifugation. An object of the present invention is to provide a sealant that allows a serum (plasma) portion to be efficiently and easily separated from a blood cell portion without being contaminated.

The demand for blood tests, which is one of the diagnostic methods for disease prevention and treatment, and Fi-medical research, is increasing year by year.

In chemical analysis of blood, serum or plasma is overwhelmingly separated from collected blood and used as a sample. This is because serum (plasma) contains information that allows us to understand pathological abnormalities in the body. In this case, it is preferable to collect as little blood as possible from the subject, and after separating the collected blood, the serum (plasma) should be collected as quickly and easily as possible to avoid recontamination with blood cells. Preparative separation is desirable. As preparative methods, decantation and siphon operations are generally carried out using automatic equipment or manually.

One of the means for facilitating the separation of serum (plasma).

There are methods for forming partition walls, and several types of separation agents for this purpose have also been proposed. These separation methods are based on the fact that while the specific gravity of serum (plasma) is generally Fil, 02 to 1.03, the specific gravity of the blood cell part is 1.08 to 1.09, which is a difference in specific gravity between the two parts. It takes advantage of the differences in properties between the liquid phase and solid phase of Yuzu serum (plasma) and blood cells.

For example, in U.S. Pat. No. 3,508,653, a piston plug is attached to the frame of a blood collection tube and descends through centrifugation to position the serum portion between the blood cells. It has the disadvantage of being dangerous.

U.S. Pat. No. 3,464,890 inserts a solid sealant of polystyrene particles with a specific gravity intermediate between serum and blood cells,
By centrifuging the blood, serum blood cells move to the middle of the two parts to form a septum layer.

However, the formed septum is weak and breaks down with the slightest impact, easily resulting in contamination of serum with blood cells.

U.S. Pat. No. 3,647,070 discloses an apparatus and method using a hydrogel pellet or plate, which is inserted into a container after blood cells have been separated, swells upon contact with serum (*!l), and creates a partition between the two parts. is formed. Since this is inserted after the blood separation operation, it is expensive and has the disadvantage of being susceptible to contamination.

A known method uses a silicone fluid with a specific gravity in the middle of the pond, but because it is a Newtonian fluid, the partition walls are easily destroyed by the slightest impact, and it has the drawback of contaminating the serum, and it is also pre-sealed in the container. There will be obstacles to transporting it.

For example, Japanese Patent Publication No. 54-2120 and Japanese Patent Publication No. 49-893
At 89, the silicon fluid is formed into a partition wall using a thixotropic gel-like material made of silicon dioxide.

Silicone fluids are generally expensive and impurities from this mixture (oil-like material floating) may develop on the surface of the serum.

In JP-A-53-42283, partition walls are formed using an acrylic polymer, but there are some drawbacks compared to the silicone Newtonian fluid mentioned above, and there is still room for improvement.

Under these circumstances, a sealant has been proposed in which acrylic fluid is used and silica powder is dispersed therein to adjust the specific gravity and impart thixotropy.However, although this invention has excellent effects as a sealant, it is difficult to manufacture. There were some difficulties. That is, when blending fine silica powder, it takes a long time to knead to obtain a stable dispersion, and the working environment is not favorable because the powder tends to scatter. Addition of Manen silica changes both specific gravity and viscosity, which poses problems such as restrictions on formulation.

As a result of intensive research, the present invention has developed a sealant that uses acrylic fluid as its main ingredient and takes advantage of its strengths as a sealant, and that not only solves manufacturing problems, but also maintains stable quality over a long period of time and exhibits excellent effects. This is what we provide.

The sealant according to the present invention can be applied either by being sealed in the blood collection tube in advance or by flowing it into the skeleton tube after blood collection. The sealant according to the invention is serum (plasma)
It is a thixotropic gel-like substance with a specific gravity between that of blood cells and blood cells, and is hydrophobic and inert to blood components. It flows easily by centrifugation operation for blood separation, and serum (
A septum layer is formed between the plasma (plasma) and blood cells. Due to the characteristics of the acrylic polymer that is the main component, this partition layer adheres well to the tube wall and exhibits a sealing effect, making it efficient without causing contamination during movement of blood collection tubes after separation operations or during serum separation operations. Serum fractionation can be performed automatically. Specifically, this sealan does not react with proteins, enzymes, lipids, inorganic ions, etc. in the blood, does not elute into the blood, and does not have any adverse effect on clinical trial test values.

The specific gravity Fi of the sealant of the present invention is 1.03 to 1.03 at 25°C
1.08, preferably Fit, osi to 1.08.
060, and the viscosity is at a shear rate of 1 s−1 at 25°C.
1500-7000 preferably 2000-5000
Indicates PS. The acrylic fluid as a main component is a product obtained by polymerizing one or more types of functional and/or non-functional alkyl acrylates and alkyl methacrylates as polymerizable monomers, and the polymerized polymers are used alone or as a blend. Can be used. The synthesis method can be carried out by a known method by selecting an appropriate solvent (toluene, xylene, butanol, etc.) and polymerization initiator (peroxide such as azobisisobutyronitrile).

After the polymerization is complete, the solvent is evaporated from the reaction mixture to yield a polymer having a solids content of about 97% by weight or more. Poly obtained in this way! - or a mixture of fluids with a specific gravity of 0.95 to 1.08 at 25°C, preferably 0.98 to 1.
08, viscosity 10-2000PS. Specific gravity is 0.9
Specific gravity is 5 or less! ! This is not preferable because the amount of inorganic fine powder used for conditioning increases, making the manufacturing process more laborious and tending to increase the viscosity too much.

If it exceeds 1.08, it loses its performance as a separating agent. The viscosity is l
o ps bt below or above 2000 PS to obtain the properties of a sealant I! Ii! ! It becomes difficult to adjust the balance between viscosity and specific gravity.

An example of an organic gelling agent for converting a polymer fluid into a gelatinous material that can be returned to the room is "Gel All J", a product of Shin Nippon Bikka Kogyo.
(D-sorbitol, a condensation derivative of aldehyde) is used, and usually the polymer fluid is heated in advance to 100 to 140° C. and added little by little to the polymer fluid while stirring to dissolve it. The amount added is preferably from $0.1 to S, O (wt%) a 0
．． It is in the range of 5 to 3.01. Inorganic fine powders added to adjust specific gravity as necessary include silicon dioxide, alumina,
Preferably, the material has a heavy specific gravity and is inert, such as titanium dioxide carbonate. The inorganic fine powder also contributes to thickening and imparting thixotropy depending on its type and amount. In addition to this! 4
Paraffin, polybutene, phosphate ester, stearate for regulating, thickening, and improving adhesive stringiness when filling sealant into blood collection tubes, improving fluidity during centrifugation, and dispersing stability of inorganic powders. , a coupling agent, etc. can also be added. The fluid for obtaining a serum separating agent by imparting thixotropic gelling properties with an organic gelling agent may be polyester, lyolefin, epoxy, etc., and is not limited to acrylic polymers. Furthermore, if the specific gravity of the fluid is heavy, it is also possible to adjust the specific gravity by using a filler that reduces the specific gravity.

It goes without saying that the sealant of the present invention is water-insoluble and inert to blood components.1 Note that when measuring the specific gravity of the sealant, the sealant is dropped to three decimal places, and the sealant remains in the middle of the solution. The specific gravity of the solution at that time was taken as the specific gravity of the sheet tent.

The viscosity was measured using a BH type viscometer with 3 cones at 25° C. and at a shearing rate of ff 1 sec-8.

*Bottom side l Add 50 parts of xylene (same weight below) to a four-loop flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer and maintain at 125°C. Knead with stirring, add 60 parts of lauryl methacrylate, ethylac') L/, +) 40
and 1.5 parts of t-butyl pert*cy 2-ethylhexanoate (Japan Oil% MM rperbutyl 0J) were continuously added dropwise over 3 hours. After the dropwise addition is completed, the mixture is stirred and kept warm at the same temperature for about 30 minutes. Next, a solution prepared by dissolving 0.8 parts of "Perbutyl 0" in 5 parts of toluene was added dropwise to Cusco 7, which was maintained at the same temperature, over 30 minutes with stirring. After the completion of the dropwise addition, the mixture was kept at the same temperature for 430 minutes with stirring and then aged to obtain a polymer solution. The temperature of this solution was gradually raised to 140°C and the solvent was removed under reduced pressure for 5 hours.
5. Poly with viscosity 1100PS! − is obtained. This polymer was transferred to a wide-mouthed container, heated to 120°C, and 1.3 parts of gelol was gradually added while stirring to ensure sufficient dissolution. The resulting gel-like material is degassed at about 100° C. under a vacuum degree of 3 to sWHg.

This tile has a specific gravity of 1,045 and a viscosity of 3 at a shear rate of 1 second.
Obtain 400 PS sealant.

Fill a glass or plastic blood collection tube with this sealant IIi and add 1.
After standing for ~60 minutes, centrifuge at 2500 rpm for 10 minutes. As a result, the blood is separated into two layers: the serum part in the upper layer and the blood cell part in the lower layer, and the sheet tent forms a layer between these two layers. Next, the upper serum portion is transferred to a collection container by decantation, but at this time, the sealan does not flow out and remains in close contact with the wall of the blood collection tube. Therefore, serum is not contaminated with blood cells.

Example 2 Polymerization and IP/solvent were carried out in the same manner as in Example 1 except that the solvent was toluene, the temperature for polymerization and insulation was 115°C, and the monomers were 40 parts of 2-ethylhexyl acrylate and 60 parts of n-butyl acrylate. Conducted, specific gravity 1.02
9. A polymer with a viscosity of 440 PS is obtained. Poly! - 1.0 part of gelol is dissolved under heating and then cooled to room temperature. Calcium carbonate fine powder (specific gravity 2
．． After dispersing and stirring 30 parts of 6-2.9), deaeration was performed in the same manner as in Example 1.

A sealant of 3300 PS is obtained at a ratio II of 1.1.045-1.050 and a viscosity shear rate of 1 sec-1. When the same blood separation test as in Example 1 was performed using this sealant, the blood was completely separated into two layers, and the sealant formed a clear separation layer between the two layers, making it easy to separate the blood during serum collection by tecantation. does not inhibit.

Example 3 Polymerization and solvent removal were carried out in the same manner as in Example 1 except that 98 parts of 2-ethylhexyl acrylate and 2 parts of lauryl methylcaptan were used, resulting in a specific gravity of 1.024 and a viscosity of 59 PS.
Obtain the following polymer. This is it! - gelol 0.5
After heating and returning to room temperature, hydrophobic silica [manufactured by Nippon Aerosil Co., Ltd. [Aerosil R972J (specific gravity 2.2
)] After dispersing 3.5 parts, deaerate. The specific gravity of this work is 1.
040-1. O45, axiality is 36 at shear rate 1 sec''1
A gel sealant of 0 o ps is obtained. 1 g of this sealant is filled into a substantially funnel-shaped plastic container having a nozzle section at the bottom. The nozzle portion of this sealant-containing container is placed over the test tube from which the blood 101 was collected and centrifuged at 3000 rpm for 5 minutes.

Due to the centrifugation operation, the sealant flows from the container nozzle into the test tube, and the blood is completely separated into two parts, serum and blood cells, and the sealant forms a separating layer between the two parts.

During serum fractionation, the sealant layer does not flow and uncontaminated serum can be obtained. .

Patent applicant: Nippon Paint Co., Ltd. #Individual fat elbow rose

Claims (1)

[Claims] (1) An organic gelling agent is dispersed in an acrylic fluid, and if necessary, an inorganic fine powder is further dispersed to form a thixotropic gel-like material, and the specific gravity at 25°C is 1.03 to 1.03. 1.08
A sealant for serum or plasma separation, characterized by having a viscosity of 1,500 to 7,000 PS. (2) Acrylic fluid is a polymer mainly composed of functional or non-functional alkyl acrylate and/or alkyl methacrylate lfi or higher as a polymerizable monomer, and has a specific gravity of 103 to 108 and a viscosity of lO to 2000 PS.
A sealant for serum or plasma separation according to claim 1, which has the following. (8) The sealant for serum or plasma separation according to claim 1, aspect 1', wherein the organic gelling agent is a condensate of higher polyhydric alcohol and benzaldehyde.