JP3062082B2 - Settling tube for liquid centrifugation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal sedimentation tube used for separating a liquid mixture which can be separated into two or more liquid phases by a difference in specific gravity using centrifugal force. Hereinafter, referred to as “centrifuge tube”).

[0002]

2. Description of the Related Art When a mixed liquid, for example, water and an organic solvent which can be separated into two liquid phases is separated into an upper liquid and a lower liquid by a difference in specific gravity using a centrifuge, a centrifuge tube is used. You.
As shown in FIG. 5, a conventional centrifugal tube includes a tubular container body 1 having an open upper surface, and a cap 2 for closing the upper surface opening of the container body 1 in a liquid-tight manner. In order to separate the mixed solution into an upper layer solution and a lower layer solution using this centrifuge tube, the mixed solution is poured into the container body 1, and the cap 2 is tightly fitted to the upper opening of the container body 1, and then the centrifuge tube is removed. Centrifuge. Thereby, the mixed liquid in the centrifuge tube is separated into the upper liquid 3 and the lower liquid 4 with a difference in specific gravity as shown in FIG.

In order to extract the lower layer liquid 4 from the upper layer liquid 3 and the lower layer liquid 4 separated in the centrifuge tube by centrifugal force, conventionally,
A method is generally used in which a syringe is used to suck all of the upper layer liquid 3 through a suction nozzle and discharge it from the container body 1 so that only the lower layer liquid 4 remains in the container body 1. In the case of manual operation, a whole pipette or pipetter is used to remove the entire upper liquid 3 from the container body 1 while visually checking the boundary surface between the upper liquid 3 and the lower liquid 4. I have.

[0004]

However, in the method of removing all of the upper liquid 3 from the inside of the container main body 1 by suctioning the upper liquid 3 through a suction nozzle with a syringe, the upper liquid 3 and the lower liquid 4 can be separated by using a photoelectric switch or the like. Although it is possible to detect only the upper layer liquid 3 from the inside of the container body 1 by detecting the position of the boundary surface of the upper layer liquid, a liquid flow occurs when the upper layer liquid 3 is sucked by the suction nozzle. Is mixed with the lower layer liquid 4 to cause contamination of the lower layer liquid 4. In the manual method using a hole pipettor or the like, the upper liquid 3 is replaced with the lower liquid 4.
When the liquid is removed up to the vicinity of the boundary with the lower liquid 4, depending on the type of liquid, a part of the upper liquid 3 is easily mixed with the lower liquid 4, so that the upper liquid 3 is not contaminated with the lower liquid 4.
There is a problem that a considerable degree of skill is required to remove only from the container body 1. Further, it is very difficult to automate such a manual method.

[0005] The present invention has been made in view of the above-described circumstances, and is based on a two-liquid system (or more liquid system) separated into an upper liquid and a lower liquid by centrifugal force. It is possible to extract only the lower layer liquid without causing contamination, and when performing the extraction operation by hand, almost no skill is required, and
It is an object of the present invention to provide a centrifuge tube in which the extraction operation can be easily automated.

[0006]

The invention according to claim 1 is
A cap which covers a top opening of a tubular container body having an open top, a through hole in the center, a tightly plugged portion which is fitted closely to an upper end of the container body, and a smaller inner diameter than the inner diameter of the container body. It is formed in a tubular shape having an outer diameter dimension, and the upper end is connected to the through hole of the hermetic plug, and the lower end is located near the inner bottom surface of the container main body when the hermetic plug is closely fitted to the upper end of the container main body. , And a closing portion that closes the lower end of the inner tube portion in a liquid-tight manner and easily falls off or bursts by a downward pressing force.

According to a second aspect of the present invention, in the centrifuge tube according to the first aspect, the closing portion of the cap is a filling plug inserted into a lower end of the inner tube portion.

In the centrifuge tube according to the first aspect of the present invention, the liquid to be separated by centrifugal force is injected into the container body, and then the inner tube portion of the cap is inserted deeply into the container body. The hermetic plug is tightly fitted to the upper end of the container body so as to be inserted into the container, and is then centrifuged in this state. Thus, the liquid in the centrifuge tube is separated into an upper liquid and a lower liquid by a difference in specific gravity. At this time, the inner tube portion of the cap is inserted into the liquid in the container body and its lower end is located near the inner bottom surface of the container body, so that the lower end of the inner tube portion is liquid-tightly closed and the upper layer is closed. It is located below the boundary surface between the liquid and the lower layer liquid, and the lower end of the inner pipe portion is inserted into the lower layer liquid. In order to extract only the lower layer liquid from the centrifuge tube in such a state, the lower end of a dispensing nozzle (a pipetter or the like when manually operated; described below using a dispensing nozzle) is sealed with a closed cap. The pipe is inserted deeply into the inner pipe through the through hole of the pipe, and the lower end of the dispensing nozzle presses the closed portion at the lower end of the inner pipe downward. As a result, the closing part closing the lower end of the inner pipe part falls off or bursts, and the lower end of the dispensing nozzle is inserted into the lower liquid. Thereafter, when the liquid is sucked into the dispensing nozzle by driving the syringe or the like, only the lower layer liquid is sucked into the dispensing nozzle because the lower end of the dispensing nozzle is inserted into the lower layer liquid.
Since the lower end of the inner tube, and thus the lower end of the dispensing nozzle, is located below the boundary between the upper liquid and the lower liquid, a part of the upper liquid mixes with the lower liquid and contaminates the lower liquid. There is no need to worry.

[0009] In the centrifuge tube according to the second aspect of the invention, the lower end of the dispensing nozzle is inserted deeply into the inner tube through the through-hole of the sealed portion of the cap, and inserted into the lower end of the inner tube. When the filling plug closing the lower end of the inner tube is pressed downward by the lower end of the dispensing nozzle, the filling plug drops off from the lower end of the inner tube and the lower end of the dispensing nozzle is inserted into the lower liquid. Is done.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the present invention. FIG. 1 is a perspective view showing a state in which a centrifuge tube is separated into a container body and a cap. FIG. It is a longitudinal cross-sectional view of the state which attached.

This centrifuge tube comprises a tubular container body 10 having an open upper surface, and a cap 12 for closing the upper surface opening of the container body 10 in a liquid-tight manner. The cap 12 includes a hermetic plug portion 14, an inner tube portion 16, and a closing portion 18. The hermetic plug portion 14 is inserted into the upper end portion of the container main body 10 and has an outer peripheral surface closely fitted thereto, and a through hole 20 is formed in a central portion. The inner tube portion 16 has an outer diameter smaller than the inner diameter of the container body 10, and has a tubular shape in which a lower portion is gradually reduced in diameter, and an upper end portion thereof is formed in an inner peripheral portion of the through hole 20 of the plug portion 14. And is integrated with the sealing portion 14. The inner tube portion 16 is formed to have a length such that the lower end thereof is located near the inner bottom surface of the container body 10 when the stopper 14 is closely fitted to the upper end portion of the container body 10. Closed part 1
Numeral 8 is formed by a filling plug that is inserted upward into the lower end of the inner tube 16, and closes the lower end of the inner tube 16 in a liquid-tight manner. The closing portion 18 made of the filling plug is easily dropped by a downward pressing force, that is, a force pressed downward by the lower end of the dispensing nozzle.

Next, a method for separating the mixed solution into an upper layer solution and a lower layer solution and extracting only the lower layer solution by using the centrifuge tube having the above structure will be described with reference to FIG.

First, after the mixed liquid is poured into the main body container 10 with the cap 12 removed, the inner tube portion 16 is inserted deeply into the container main body 10 so as to be inserted into the liquid. The cap 12 is attached to the container body 10 such that the cap 12 is tightly fitted to the upper end of the container body 10. By centrifuging the centrifuge tube in this state, as shown in FIG. 3, the liquid contained between the inner peripheral surface of the container body 10 and the outer peripheral surface of the inner tube portion 16 of the cap 12 becomes the upper layer liquid 22. And the lower layer liquid 24. At this time, as shown in FIG. 3A, since the lower end of the inner tube 16 of the cap 12 is located near the inner bottom surface of the container body 10, the lower end of the inner tube 16 is Interface 26 between lower fluid 22 and lower layer liquid 24
It is located below. Therefore, the vicinity of the lower end of the inner pipe portion 16 is in a state of being inserted into the lower layer liquid 24.

Next, in order to extract only the lower layer liquid from the centrifuge tube by an automatic dispensing device (the whole configuration is not shown), the centrifuge tube is fixed to a mounting portion (not shown) of the automatic dispensing device. .
Subsequently, the dispensing nozzle 28 is lowered by a nozzle driving mechanism (not shown) as shown in FIG. 3A, and the lower end of the dispensing nozzle 28 is formed as shown in FIG. 3B. Disposable chips (hereinafter referred to as “disposable chips”)
) 30 is inserted deeply into the inner tube portion 16 through the through hole 20 of the plug portion 14 of the cap 12 of the centrifuge tube. Then, the lower end of the disposable tip 30 presses the closing portion 18 at the lower end of the inner tube portion 16 downward, thereby closing the closing portion 18 formed of a filling plug as shown in FIG. , And the lower end of the disposable chip 30 is inserted into the lower layer liquid 24. Thereafter, the dispensing nozzle 28
By driving a syringe (not shown) connected to the dispenser chip 30, a liquid is sucked into the disposable chip 30 through the lower end opening of the disposable chip 30. At this time, since the lower end of the disposable chip 30 is inserted into the lower layer liquid 24,
Only the lower layer liquid 24 is sucked into the disposable chip 30, and the lower end of the disposable chip 30 is connected to the upper layer liquid 22 and the lower layer liquid 2.
Because it is located much lower than the boundary surface 26 with 4,
There is no concern that a part of the upper liquid 22 is mixed with the lower liquid 24 to cause contamination.

The centrifugal tube whose longitudinal section is shown in FIG. 4 has a structure in which the hermetically sealed portion 34 of the cap 32 is placed over the upper end of the container body 10 and externally fits in a liquid-tight manner. The upper end of the inner tube portion 36 is fixed to the inner peripheral portion of the hole 40, so that the plug portion 34 and the inner tube portion 36 are integrated. Further, a thin plate portion is integrally formed at the lower end of the inner tube portion 36 to form a closing portion 38. The closing portion 38 formed of the thin plate portion is easily ruptured by being pressed downward by the lower end of the dispensing nozzle.

In each of the above embodiments, the cap 12,
Although the hermetic plug portions 14 and 34 and the inner tube portions 16 and 36 which constitute 32 are separate from each other, and the inner tube portions 16 and 36 are fixed to the hermetic plug portions 14 and 34 to integrate them, You may make it integrally form with an inner tube part. In addition, the configuration of the closing portion that closes the lower end of the inner pipe portion in a liquid-tight manner and easily falls or ruptures by a downward pressing force is formed by integrally forming a thin plate-shaped portion at the lower end of the filling plug or the inner pipe portion described in the above embodiment. The present invention is not limited to this, and may have a configuration in which, for example, the lower end of the inner tube portion is covered with a film and closed in a liquid-tight manner. Further, in the above description based on FIG. 3, only the lower layer liquid is extracted from the centrifuge tube by the automatic dispensing device. However, only the lower layer liquid is extracted from the centrifuge tube manually by using a hole pipettor or the like. Of course, it is also possible.

[0018]

According to the centrifuge tube according to the first aspect of the present invention, contamination of the upper liquid from the two liquid phase system or more liquid phase system separated into the upper liquid and the lower liquid by centrifugal force is achieved. Only the lower layer liquid can be extracted without producing any nation. When the extraction operation is performed manually, almost no skill is required. On the other hand, when the extraction operation is to be performed automatically,
Its automation is easy.

In the centrifuge tube according to the second aspect of the invention, the lower end of the dispensing nozzle or pipettor is inserted deeply into the inner tube of the cap, and the closed portion is pressed downward by the lower end of the dispensing nozzle or the like. As a result, the closing portion formed by the filling plug easily falls off, and the lower end of the dispensing nozzle or the like can be inserted into the lower layer liquid, and only the lower layer liquid can be extracted.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a state in which a centrifuge tube according to one embodiment of the present invention is separated into a container body and a cap.

FIG. 2 is a longitudinal sectional view showing a state in which a cap is attached to the container main body of the centrifuge tube shown in FIG.

FIG. 3 is a longitudinal sectional view for explaining an operation of using the centrifuge tube shown in FIGS. 1 and 2 to separate a mixed solution into an upper liquid and a lower liquid and extract only a lower liquid.

FIG. 4 is a longitudinal sectional view of a centrifuge tube showing another embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of a conventional centrifuge tube.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Container body of centrifuge tube 12, 32 Cap of centrifuge tube 14, 34 Sealing part of cap 16, 36 Inner tube part of cap 18, 38 Capping part of cap 20, 40 Through-hole of sealing part 22 Upper liquid 24 Lower liquid 26 Interface between upper and lower liquids 28 Dispensing nozzle

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shintaro Nishimura 4-3-34-517, Tsuruno, Settsu-shi, Osaka (72) Inventor Masayoshi Murata 7-7-17, Higashi Tokiwadai, Toyono-cho, Toyono-gun, Osaka (56) References JP-A-1-297161 (JP, A) JP-A-58-48351 (JP, U) JP-A-49-65090 (JP, U) JP-A-57-131856 (JP, U) JP-A-49-32692 (JP, U) J. 25-1461 (JP, Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) B04B 5/02

Claims (2)

(57) [Claims] A tubular container body having an open upper surface;
In a sedimentation tube for centrifugal separation of a liquid, comprising a cap covered on an opening on the upper surface of the container body, the cap having a through hole in a central portion, and a tightly plug portion which is closely fitted to an upper end portion of the container body. And a tubular shape having an outer diameter smaller than the inner diameter of the container body, the upper end is connected to the through hole of the plug, and the lower end is tightly fitted when the plug is tightly fitted to the upper end of the container. An inner tube formed to have a length near the inner bottom surface of the container body; and a closing portion that closes the lower end of the inner tube in a liquid-tight manner and easily falls off or bursts by a downward pressing force. A sedimentation tube for centrifugal separation of a liquid, comprising: 2. The sedimentation tube for centrifugal separation of liquid according to claim 1, wherein the closing portion is a filling plug inserted into a lower end of an inner tube portion of the cap.