JPS6256461B2 - - Google Patents

Description

[Detailed Description of the Invention] Background Technical Field of the Invention The present invention relates to a serum separation member used to separate only serum components from blood, and is particularly suitable for use in an automatic serum separation device using a suction nozzle. The present invention relates to a serum separation member.

Prior Art and Problems Conventionally, only serum components have been separated by centrifugation using a serum separation member (or barrier) with a specific gravity intermediate between serum components and blood clot components. Although many proposals have been made as members for serum separation, they are still not satisfactory in terms of obtaining a high yield of serum free of impurities such as blood clots and fibrin. In particular, there were many problems when using an automatic serum fractionator using a suction nozzle.

For example, a method is known in which plastic beads having an intermediate specific gravity are used as a serum separation member, but with this method, the serum present between the beads cannot be fractionated, resulting in a low serum collection rate. A method using a plastic disc with an intermediate specific gravity is also known, but with this method, a thin sedimentary layer of blood cells is formed on the top surface of the disc, which may be mixed into the collected serum. Serum remains around the clot below the plate, reducing yield. moreover,
A method using a gel-like substance having an intermediate specific gravity is also known, but with this method, there is a risk that oil may separate from the gel-like substance or the gel-like substance may adhere to the suction nozzle.

Purpose of the Invention This invention has been made in view of the above circumstances, and provides a high serum yield and blood cells and
It is an object of the present invention to provide a serum separation member that can prevent contamination with fibrin and the like and is particularly suitable for use in an automatic serum separation device using a suction nozzle.

That is, this invention uses soft plastic with a specific gravity of 1.05 to 1.1,
It is constructed in a substantially cylindrical shape with an outer diameter of a cross section that is slightly smaller than the inner diameter of the separation tube to be used; one end thereof has a tapered protruding surface that forms an inclination of 15 to 30° with respect to the cross section. has a through hole that communicates from the top of the protruding surface to the other end; the other end has an open end of a large diameter cavity that communicates with the through hole through the top of the rotating object surface; It is characterized by having a plurality of protrusions which are provided on the cylindrical outer peripheral wall surface at equal intervals in the circumferential direction and whose tips are pressed into contact with the inner wall surface of the separation tube to be used. The present invention provides a serum separation member.

The present invention further provides the serum separation member described above, wherein the soft plastic is a blend polymer of chlorinated polyethylene and ethylene/vinyl acetate copolymer.

Furthermore, the present invention provides the serum separation member described above, wherein the through hole has a diameter of 1 to 3 mm and a thickness of 1 to 3 mm.

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below based on illustrated embodiments.

In the figure, reference numeral 1 denotes a serum separation member according to the present invention, which is made of a blend polymer (specific gravity 1.05) containing, for example, chlorinated polyethylene and ethylene vinyl acetate copolymer in a ratio of 10:4 and molded into an approximately cylindrical shape. (The specific gravity can be appropriately selected by changing the blending ratio). To explain this in more detail, this serum separation member 1 has an outer diameter (in cross section) that is slightly smaller than the inner diameter of the separation tube to be used.
Preferably, the outer diameter is 0.6 to 1.4 mm smaller than the inner diameter of the separation tube, and one end thereof is configured with a tapered protruding surface 2. The slope θ of the protruding surface 2 is preferably in the range of approximately 15 to 30 degrees with respect to the cross section (broken line a). If it is smaller than this lower limit, there is a risk that a sediment layer of blood cells will be formed on the protruding surface 2, and if it is larger than this upper limit, there is a risk that a large amount of serum that cannot be fractionated by the suction nozzle will remain.

A through hole 3 is bored at the top of the tapered projecting surface 2 and communicates from the top of the projecting surface to the other end.
This through hole 3 is for allowing serum to pass through during centrifugation. The inner diameter of the through hole 3 may be 5 mm or less when the blood is sufficiently coagulated and a blood clot is completely formed, and preferably about 1 to 3 mm. If it is below this lower limit, there is a risk of clogging due to fibrin, or because the rising serum flow becomes faster, blood cells may rise or pass through. If it is above this upper limit, it is unfavorable from the standpoint of serum remaining. For the same reason, the depth of the through hole 3 can range from 5 to 6 mm, but is preferably about 1 to 3 mm.

The other end of the serum separation member 1 constitutes the open end of a large-diameter cavity 5 that communicates with the through hole 3 through a rotating object-shaped (or egg-tip shaped) top 4.

Above the outer circumferential wall surface of the serum separation member 1 (or at the lower end of the tapered protruding surface 2), four protrusions 6 are provided at equal intervals in the circumferential direction and protrude outward by about 0.35 mm in the horizontal direction. This protrusion 6 secures an upward passage for serum around the blood clot layer or a downward sedimentation passage for blood cells sedimented on the protruding surface 2 between the inner wall of the separation tube and the serum separation member 1 during centrifugation operation. In addition, after the centrifugation operation, the blood clot layer is prevented from being pushed up from below due to the restoring force, and the serum yield is prevented from decreasing, and the suction nozzle of the automatic serum separation device comes into contact with the top surface of the serum separation member The function is to ensure that the serum separation member 1 remains stationary against the impact caused by the vibration, and to prevent blood cells, fibrin, etc. from flying up. Therefore, when the tips of the protrusions 6 are housed in the separation tube, they are in even pressure contact with the inner wall surface thereof, and the degree of pressure contact is such that they can easily slide under the stress of centrifugation operation. In addition, it is necessary to design the device to the extent that it can sufficiently resist the external force applied after the centrifugation operation is completed. The protrusion 6 shown in Fig. 2 is shown with its tip facing upward, and is designed to have greater resistance to stress from below (force pushing up blood clots) than stress during centrifugation. There is.

The shape of this protrusion is not limited to that shown in Fig. 2, but may be a downward protrusion 6a as shown in Fig. 3, or an acute-angled tip as shown in Figs. 2 and 3, as shown in Fig. 4. Rather than having a flat shape, it may be possible to select a shape having an arbitrary shape as needed, such as having a flat tip, taking into consideration the material and other factors.

The length of the serum separation member 1 needs to be long enough so that there is no risk of the orientation being overturned during centrifugation, and is appropriately determined by taking into account the inner diameter of the separation tube to be used. Relatively flexible plastic materials (e.g.
JIS hardness of 70 to 85), and in order to be able to slide while being in pressure contact with the inner wall of the separation tube when centrifuged at around 1000G, the specific gravity should be 1.04 or more;
A value of about 1.05 to 1.1 is preferable because it allows a wide range of centrifugation conditions to be set. If the blood is sufficiently coagulated and a blood clot has been completely formed, the blood clot will catch the serum separation member and prevent further sedimentation even if the specific gravity is higher than that of the blood clot. In this case, the larger the specific gravity, the stronger the force that suppresses the blood clot during centrifugation, and the higher the serum yield.

Next, a method of using the serum separation member according to the present invention will be explained.

First, the blood collection tube is left for a certain period of time to sufficiently solidify, and then inserted into the separation tube with the other end opening facing downward. Then, for example
When centrifugation is performed for about 10 minutes with a centrifugal force of around 1000G, the serum separation member 1 settles while sliding in contact with the projections 6, and the serum is separated from the through hole 3, the serum separation member 1, and the inner wall of the separation tube. move upward through the gap between Further, the serum separation member 1 captures the head of the blood clot through the cavity 5 and settles down while wrapping the blood clot with its hem, while the serum layer 10
The mixed blood cells are deposited on the tapered protruding surface 2, and at the same time, due to the slope of the protruding surface 2, they gradually move toward the inner wall of the separation tube 9, and pass through the gap between the serum separation member 1 and the blood cells used for serum separation. It settles below the member 1, and finally the head 8 of the blood clot 7 as shown in FIG.
The serum layer 10 and the blood clot 7 are separated in such a state that the blood clot 7 is fitted into the cavity 5 of the serum separation member 1. In this case, substantially no serum remains between the cavity 5 and the head 8 of the blood clot 7. This is because the head 8 of the blood clot 7 formed during coagulation is caught by the open end of the cavity shaped like a large-diameter rotating object, and the head of the blood clot is guided into the cavity while holding down the blood clot. The blood clot, which resembles a cotton ball containing water, deforms as if fitting into the cavity, leaving no room for serum to remain between them, and the repulsive force of the blood clot due to the action of the projections. This is because the serum separation member will not be pushed up. The most preferable shape of the cavity for performing such a function is the cavity shaped like the surface of a rotating object. Furthermore, when the stress due to centrifugal force is reduced at the end of the centrifugation operation, the restoring force of the blood clot acts on the serum separation member 1, but the separation tube 9 of the protrusion 6
The serum separation member 1 will not be returned upward due to the frictional force against the serum separation member 1.

The thus separated serum 10 is fractionated by decantation or by an automatic serum fractionator using a conventional method.

As described in detail above, according to the present invention, it is possible to sufficiently separate serum around a blood clot, and it is also possible to prevent serum from remaining between the serum separation member and the head of the blood clot. As a result, the serum yield is significantly improved compared to conventional methods, and furthermore, no blood cell layer remains on the top surface of the serum separation member, and the suction nozzle of the automatic serum separation device does not come into contact with the serum separation member. It also prevents blood cells, fibrin, etc. from flying up, as it maintains a stationary state against the impact, so even when using an automatic serum separation device with a suction nozzle, there is no possibility of contamination with blood cells, etc. during separation. can be effectively prevented. Therefore, it is particularly suitable when using an automatic serum fractionator.

[Brief explanation of the drawing]

The drawings show an embodiment of the serum separation member according to the present invention, in which FIG. 1 is a plan view showing the upper surface of the serum separation member, FIG. 2 is a sectional view taken along the line - in FIG. 3 and 4 are sectional views of essential parts showing modified examples of the protrusion, respectively, and FIG. 5 is a sectional view showing how the serum separation member shown in FIG. 1 is used. In the figure, 1...Serum separation member, 2...Protruding surface,
3...Through hole, 4...Rotating object surface, 5...Cavity part,
6, 6a, 6b...Protrusion, 7...Blood clot, 8...Blood clot head, 9...Separation tube, 10...Serum.

Claims (1)

[Scope of Claims] 1. Made of soft plastic with a specific gravity of 1.05 to 1.1, it is constructed in a substantially cylindrical shape with an outer diameter in cross section that is slightly smaller than the inner diameter of the separation tube to be used;
One end thereof has a tapered protruding surface that forms an inclination of 15 to 30 degrees with respect to the cross section; it has a through hole that communicates from the top of the projecting surface to the other end; The rotating object constitutes an open end of a large diameter cavity that communicates with the top of the object surface; provided on the cylindrical outer peripheral wall surface at equal intervals in the circumferential direction,
A serum separation member characterized by having a plurality of protrusions whose tips are brought into pressure contact with the inner wall surface of a separation tube to be used. 2. Claim 1, wherein the soft plastic is a blend polymer of chlorinated polyethylene and ethylene/vinyl acetate copolymer.
Serum separation member described in Section 1. 3. The serum separation member according to claim 1 or 2, wherein the through hole has a diameter of 1 to 3 mm and a thickness of 1 to 3 mm.