JP2001050968A - Pipetter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase adhesion between the main body section and pipette chip of a pipetter, even if the inside or outside diameter of the top opening of the chip varies, and at the same time, to make the chip easily detachable from the main body section. SOLUTION: In a pipetter, a main body section 2, has an air passage for sucking air from the inside of a pipette chip 1 having a sucking and discharging port 1A for sucking and discharging a liquid at its front end, or sending air into the chip 1, is attached to the top opening 1B of the chip 1. An expanded body 5, which can be expanded by injecting a liquid, is attached to the main body section 2 and is closely adhered to the inner peripheral surface 1C or outer peripheral surface of the chip 1 on the top opening 1B side by expanding the body 5, by injecting the liquid from a liquid supplying and discharging flow passage 6 which is formed in the main body section 2 separately from the air passage 3, so that the chip 1 is seized by the expanded body 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pipettor which is a kind of instrument for measuring a fixed volume of liquid. In particular, a suction / drain port for sucking and discharging a liquid at the tip, a pipette tip having an opening at an upper end is attached and detached, and a means for sucking air in the pipette tip or sending air into the pipette tip is provided. It relates to a pipettor with an improved main body.

[0002]

2. Description of the Related Art The inside diameter of the upper end opening of a conventional pipette tip is 4 mm, 5 mm, 8.5 mm, 11 mm, and 13 m.
m and several types, and a nozzle cone was provided in the main body in accordance with this inner diameter. This nozzle cone has elasticity, is formed in a size corresponding to the diameter of each chip, and is fitted to the chip from the upper end opening of the chip (like a plug in the opening). It had been kept sealed. An air passage is formed between the nozzle cone and the main body, and the liquid in the pipette tip is weighed by sucking air in the chip from the air passage. The liquid is discharged by sending air into the chip.

[0003]

Most pipette tips are made of polypropylene, and most of them are disposable. If the inner diameter of the pipette tip changes due to heat or the outer diameter of the nozzle cone changes, the degree of adhesion of the nozzle cone to the inner peripheral surface of the tip changes, and the adhesion and sealing properties may deteriorate. Was. In addition, when the liquid is discharged at a high speed or when a highly viscous liquid is discharged, the internal pressure in the chip increases, so that a nozzle having a higher adhesion force of the nozzle cone to the chip has been required. Further, in the conventional method of fitting a nozzle cone, there is a possibility that it may be difficult to attach and detach the chip when the adhesion of the nozzle cone to the chip is increased.

Accordingly, the present invention provides a pipettor which has a high adhesion between the main body and the tip even when the inner or outer diameter of the upper end opening of the pipette tip changes, and which allows the tip to be easily detached from the main body. The purpose is to:

[0005]

In order to achieve the above-mentioned object, the present invention suctions air in a pipette tip to an upper end opening side of a pipette tip having a suction / discharge port for sucking / discharging a liquid at a tip. In a pipettor equipped with a main body having an air passage for sending air into a pipette tip, an inflatable body that expands by injection of a fluid is attached to the main body, and is formed in the main body separately from the air passage. A pipette tip is gripped by the inflatable body by injecting a fluid into the inflatable body from a fluid supply / discharge channel and inflating the inflatable body to the inner or outer peripheral surface of the pipette tip at the upper opening side. It is.

[0006]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.

The embodiment shown in FIG. 1 shows a half section just before the pipette tip 1 is mounted on the main body 2, a suction / discharge port 1A for sucking and discharging liquid is provided at the tip of the pipette tip 1, and at the upper end. An opening 1B is provided. The main body 2 is provided with an air passage 3 for sucking and sending air in the chip 1. In this embodiment, the air passage 3 is formed in the air passage 4, and the air passage 4 is connected to the main body 2. It is inserted through and fixed to the center of the main body 2 so as to protrude up and down. Further, an inflatable body 5 which is expanded by injection of a fluid such as air is attached to the main body 2. In this embodiment, a tubular inflatable body is provided on the outer periphery of a downwardly protruding insertion portion 41 (lower part of the air duct). 5
The inflatable body 5 extending downward from the one end 5A is folded back (returned portion 50), and the other end 5B is secured to the outer periphery of the main body 2. Then, a fluid supply / discharge flow path 6 is formed in the main body 2 separately from the air passage 3, and the fluid sent from this flow path 6 is a portion of the inflatable body 5 that is overlapped above the folded portion 50. To expand the expansion body 5 outward. The inflated portion of the inflatable body 5 is tightly pressed against the inner peripheral surface 1C of the pipette tip 1. In this state, the pipette tip 1 is mounted in close contact with the main body 2, and when the fluid is discharged from the flow path 6 to the outside, the expansion body 5
Can be reduced to easily remove the pipette tip 1 from the main body 2.

An external thread 2A is formed on the upper outer periphery of the main body 2, and is formed on the upper inner peripheral surface of the nut member 7 fitted from below the main body 2, so that the screw 7A is formed by the external thread 2A.
To screw. This nut member 7 is connected to the other end 5B of the expansion body 5.
Is clamped by the outer periphery of the main body 2. It should be noted that the nut member 7 is fixed so that the fluid supplied from the flow path 6 does not leak from the other end 5B sandwiched between the main body 2 and the nut member 7.
A packing 7B is provided on the upper part of the box, and is sealed and fixed. Further, an annular groove 4A is formed on an outer periphery of a portion protruding below the insertion portion 41, and a male screw 4B is formed on an outer periphery below the annular groove 4A. The female screw 8B of the pipe portion 8A of the guide member 8 is screwed to the male screw 4B. At the upper end of the pipe portion 8A, one end 5A of the expansion body 5 fitted in the annular groove 4A is vertically clamped. Further, a passage 8C communicating with the air passage 3 is formed in the guide member 8, and supply and discharge of air into and from the pipette tip 1 are performed as follows.
This is performed via the air passage 3 and the passage 8C.

The main body 2, the air conduit 4, and the nut member 7 can be formed of a plastic material. Further, the guide member 8 can be formed of a similar plastic material. As the expansion body 5, a tube body having a thicker one end 5A can be suitably used. The shape of the inflatable body 5 before the fluid is injected has a tapered shape with a small diameter at the tip and a large diameter at the upper end, and follows the tapered shape of the inner peripheral surface 1C of the pipette tip 1.
Since the shape of the normal pipette tip 1 is tapered so that the diameter increases toward the upper end opening 1B, the portion of the expansion body 5 facing the inner peripheral surface 1C should also be formed in the same tapered shape. Thereby, the adhesiveness at the time of expansion is improved.

In the embodiment shown in FIG. 2, one end 5A of the inflatable body 5 is brought into contact with a male screw 4B formed at the lower end of the insertion portion 41, and the male screw 8B formed on the inner periphery of the guide member 8 is used. It is screwed to the screw 4B so that the one end 5A of the expansion body 5 is sandwiched by the upper end side of the guide member 8. The expansion body 5 extends straight upward without folding, and the other end side 5B extends to the outer periphery of the main body 2. Installed. Nut member 7 and main body 2
The inflatable body excluding the portion of the inflatable body 5 and the portion of the one end side 5A sandwiched between them has a tapered shape on the distal end side, and conforms to the tapered shape of the inner peripheral surface 1C of the pipette tip 1. The fluid from the flow path 6 is supplied to and discharged from the space between the expansion body 5 and the insertion portion 41.

In the embodiment shown in FIG. 3, the inflatable body 5 is molded from a rubber material or the like so as to maintain a predetermined shape, and the insertion portion 41 is inserted into a portion formed in the inner pipe-like portion 5C. And the other end 5B is fixed to the outer periphery of the main body 2 with a caulking ring 9. Even when the pipe-shaped portion 5C of the expansion body 5 is not particularly fixed to the insertion portion 41, when the fluid is injected from the flow path 6, the pipe-shaped portion 5C is brought into close contact with the outer circumference of the pipe-shaped portion 5C by the pressure of the fluid. Is inflated outward, and the inflated portion is in close contact with the inner peripheral surface 1C of the pipette tip 1.

In the embodiment shown in FIG. 4, a tube body such as a rubber tube having sufficient flexibility is used as the inflatable body 5, and the lower end of the main body 2 has an end 5A on the small outer diameter side.
An example is shown in which the other end 5B is folded back on the outer peripheral surface having a large diameter on the upper end side of the main body portion 2 and fixed by the swaging ring 9.

FIG. 5 shows an embodiment in which the inflatable body 5 is in close contact with the outer peripheral surface of the pipette tip 1 instead of the inner peripheral surface 1C. That is, an outer periphery of the main body 2 extends downward with a predetermined thickness to form a cylindrical body 21, and an air passage forming portion of the main body 2 extends downward and is inserted into the cylindrical body 21. A portion 41 is formed, and an insertion hole 51 through which the insertion portion 41 is inserted is provided at one end of the expansion body 5. The other end 5B of the expansion body 5 is opened, and the other end 5B is folded back and fixed by the caulking ring 9 on the outer peripheral surface of the cylindrical body portion 21. The inflatable body 5 extends along the inner wall of the cylindrical body 21 at the other end 5.
B is folded back and fixed to the outer peripheral surface of the cylindrical body portion 21 by the caulking ring 9. Further, the fixing plate 10 is provided at the insertion portion 41 inserted through the insertion hole 51 of the expansion body 5 so that the main body 2
And the fixing plate 10 is fixed with one end of the expansion body 5 therebetween. Further, the outer peripheral surface near the upper end opening 1B of the pipette tip 1 is formed not in a tapered shape but in a straight portion 1C, and the inflatable body 5 bulging inward on the straight portion 1C is tightly gripped. I do.

FIG. 6 shows an embodiment in which the guide member 8 is used in a type in which the outer peripheral surface of the pipette tip 1 is gripped by the inflatable body 5.
An example in which 0 is provided is shown. The other end 5 </ b> B of the expansion body 5 is fixed to the guide member 80 and the lower end of the cylindrical body 21 of the main body 2.

As shown in FIG. 7, a plurality of reinforcing cords 51 are preferably embedded in the inflatable body 5 so as to be parallel to the axis of the main body 2. FIG. 8 shows a horizontal section of a development view of the expansion body 5 shown in FIG. It is necessary to increase the fluid pressure in order to increase the adhesive force of the expansion body 5 to the pipette tip 1. Therefore, embedding the reinforcing cord 51 in the expansion body 5 is necessary to increase the durability of the expansion body 5. It is valid.

The expansion body 5 shown in FIGS. 9 and 10 is one in which the reinforcing cords 51 are embedded so as to be inclined with respect to the axis of the main body 2 and to cross each other.
The inclination angle θ is set to 20 ° or less. When the inclination angle θ of the reinforcing cord 51 exceeds 20 °, when the inflatable body 5 is inflated, especially when the folded portion 50 is provided, the portion 50 rises and expands in the lateral direction. 2 and the expansion ratio does not increase in spite of the effective length of the expansion body 5. When the angle θ is less than 20 °, the expansion magnification becomes large.

FIG. 11 shows a state in which the main body 2 to which the above-mentioned one pipette tip 1 is mounted is attached to the main body 30. The external thread 2A of the main body 2 is formed in the main body 30. It is screwed into the screw 31. Also, a separator 32 made of an elastic material is attached to the air line 4,
The fluid can be separately supplied to and discharged from the air pipe 3 and the flow path 6. A large number of main units 2 can be attached to such a main unit.

FIG. 12 shows the main unit 30 provided with an elastic member 33 instead of the female screw 31, and the main unit 2 is inserted into an insertion opening surrounded by the elastic member 33 to seal each other.

In the embodiment shown in FIGS. 13 and 14, a plurality of pipette tips 1 are mounted on the main body 2;
In this embodiment, three chips 1 are mounted on the main body 2.

In the embodiment shown in FIG.
Fixed three air pipes 4 projecting up and down,
Each air line 4 forms an air passage 3 for sucking and sending air in the chip 1. Each air line 4 includes an air tube 42 (above the air line) provided above the main body 2,
It has an insertion part 41 (lower part of the air duct) projecting below the main body part 2, and a male screw 4 </ b> B is formed on the outer periphery below the insertion part 41. In this embodiment, an inflatable body 5 that expands by injection of a fluid such as air is attached to a main body 2 and a fixing plate 1 that fixes the inflatable body 5 to the main body 2.
0 is provided. In addition, the inflatable body 5 includes a tubular lower protruding portion 5D provided on the outer periphery of each insertion portion 41,
And a flat portion 5E fixed below the main body 2 by the fixing plate 10. That is, the expansion body 5
Is a portion extending downward from the hole 11 of the fixing plate 10 and provided on the outer periphery of the insertion portion 41 (a downward protruding portion 5D).
And a portion (flat portion 5E) extending along the upper surface of the fixing plate 10 and fixed below the main body 2.

Further, one end 5A of the lower protruding portion 5D of the inflatable body is fixed to the outer periphery of the insertion portion 41, and the inflatable body extending downward from the one end 5A is folded back (the folded portion 5A).
0), forming a superposed portion of the expansion body. Insertion part 4
1 and the lower protruding portion 5D of the expansion body provided on the outer periphery protrude downward through the hole 11 of the fixed plate 10. The flat portion 5E of the expandable body has a peripheral edge 5F formed with a large thickness. The expandable body is sandwiched between the lower surface of the main body 2 and the fixing plate 10, and the peripheral edge 5F is fixed to the lower surface of the main body 2. A fluid passage 61 is formed between the flat portion 5 </ b> E of the expansion body and the main body 2. The fluid injected from the fluid supply / discharge channel 6 provided in the main body 2 separately from the air passage 3 passes through the fluid passage 61 and is fed into the overlapped portion above the folded portion 50 of the expansion body 5. Then, the lower protruding portion 5D of the expansion body provided on the outer periphery of the insertion portion 41 is expanded outward. The fixing plate 10 is a bolt member 71
The peripheral edge 5 </ b> F comes into pressure contact with the lower surface of the main body 2 by tightening the bolt 71, so that the peripheral edge 5 </ b> F adheres tightly.

The female thread 8B of the pipe 8A of the guide member 8 is screwed to the external thread 4B of the insertion portion 41. A passage 8C communicating with the air passage 3 is formed in the guide member 8, and supply and discharge of air into and from the mounted pipette tip 1 are performed via the air passage 3 and the passage 8C.

The main body 2, the air conduit 4, and the bolt member 71 can be formed of a plastic material. Further, the guide member 8 can be formed of a similar plastic material. The inflatable body 5 may be molded with a rubber material or the like so as to maintain a predetermined shape.
In addition, as the expansion body 5, a tube body having a thicker peripheral edge 5F and one end 5A can be suitably used.
Further, the tube-shaped inflatable body (downward protruding portion 5D) provided on the outer periphery of the insertion portion 41 has a tapered shape with a small diameter at the tip and a large diameter at the upper end before injecting the fluid. It is preferable to follow the tapered shape of the inner peripheral surface 1C. Since the shape of the normal pipette tip 1 is tapered such that the diameter increases toward the upper end opening 1B, the portion of the expansion body 5 facing the inner peripheral surface 1C (the downward protruding portion 5) also has the same tapered shape. In this case, the adhesiveness during expansion is improved.

Also in this embodiment, it is preferable to embed a plurality of reinforcing cords in the inflatable body 5 like the inflatable body 5 shown in FIGS. 7 to 10 described above. In order to increase the adhesive strength of the inflatable body 5 to the pipette tip 1, it is necessary to increase the fluid pressure.
It is effective to embed 1 to increase the durability of the expansion body 5.

FIG. 14 is a sectional view of an embodiment in which a plurality of pipette tips are mounted. The main body 2 for mounting three pipette tips 1 is for sucking and sending air in each tip 1. Three air passages 3 are provided. In this embodiment, three air passages 4 provided in the main body 2 form the air passages 3. In addition, a fluid supply / discharge flow path 6 is formed in the main body 2 separately from the air passage 3. Fluid supplied from the flow path 6 is supplied between the main body 2 and the inflatable body 5 (flat portion 5E). Through the fluid passage 61 formed in
It is fed into a tube-shaped inflatable body 5 (a downward protruding part 5D) provided on the outer periphery of the insertion portion 41, and the inflatable body 5 provided on the outer periphery of the insert portion 41 is expanded outward, whereby the inner peripheral surface 1C of the pipette tip 1 is expanded. Press closely against Pipette tip 1 in this state
Is mounted in close contact with the main body 2, and when the fluid is discharged from the flow path 6 to the outside, the tubular inflatable body 5
The (lower protruding portion 5D) is reduced so that the pipette tip 1 can be easily removed from the main body 2.

[0026]

As described above, according to the present invention,
When the pipette tip is attached to the main body, the inflatable body is expanded and brought into close contact with the inner or outer peripheral surface of the pipette tip,
Since the tip is grasped by the inflatable body, the pressure of the fluid to be injected is increased to improve the adhesion of the inflatable body to the pipette tip, and the main body is maintained even when the inner or outer diameter of the upper end opening of the pipette tube changes. It does not cause a decrease in the adhesion between the pipette tip and the tip, and the pipette tip can be easily attached to and detached from the main body by supplying and discharging the fluid.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a preferred embodiment of the present invention.

FIG. 2 is a half sectional view showing another embodiment.

FIG. 3 is a sectional view showing another example of the main body.

FIG. 4 is a sectional view showing still another example of the main body.

FIG. 5 is a sectional view showing another embodiment.

FIG. 6 is a sectional view showing another example of the guide member.

FIG. 7 is an exploded view of an expansion body in which a reinforcing cord is embedded in the expansion body.

FIG. 8 is a horizontal sectional view of FIG. 7;

FIG. 9 is a development view of an inflatable body in which the embedding method of the reinforcing cord is changed.

FIG. 10 is a horizontal sectional view of FIG. 9;

FIG. 11 is a sectional view showing a state where the main body is attached to the main body device.

FIG. 12 is a sectional view showing another example of the main device.

FIG. 13 is a three-dimensional exploded view of an embodiment in which a plurality of pipette tips are mounted.

FIG. 14 is a sectional view of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pipette tip 1A suction / discharge port 1B upper end opening 1C inner peripheral surface 2 main body 3 air passage 5 inflatable body 6 flow path 8 guide member 41 insertion section

Claims (16)

[Claims] 1. A main body having an air passage for sucking air in the pipette tip or sending air into the pipette tip at an upper end opening side of a pipette tip having a suction / discharge port for sucking / discharging a liquid at a tip. In the pipettor with the part attached, an inflatable body that expands by injecting a fluid is attached to the main body part, and a fluid is injected into the inflatable body from a fluid supply / discharge channel formed in the main body part separately from the air passage. A pipettor, characterized in that the expanded inflatable body is brought into close contact with the inner peripheral surface or the outer peripheral surface of the upper end opening side of the pipette tip so that the inflatable body grips the pipette tip. 2. An air passage forming portion of the main body portion extends downward to form an insertion portion to be inserted into a pipette tip,
One end of a tubular inflatable body is contacted or fixed to the outer periphery of the insertion portion, the inflatable body is folded back from a predetermined length, and the other end is fixed to the outer periphery of the main body. 2. The structure according to claim 1, wherein a fluid is injected into a space of the overlapped portion of the inflatable body by inserting the fluid into the pipette tip, and the outer inflatable surface of the inflatable body is pressed against the inner peripheral surface of the pipette tip. Pipettor. 3. The pipettor according to claim 2, wherein a guide member provided with a passage communicating with an air passage of the insertion portion is provided at a tip of the insertion portion. 4. An air passage forming portion of the main body portion extends downward to form an insertion portion to be inserted into a pipette tip,
The inner peripheral surfaces of both ends of the tubular inflatable body are fixed to the guide member according to claim 3 provided on the outer periphery of the insertion portion or the distal end of the insertion portion and the outer periphery of the main body portion, and fluid is inserted between the insertion portion and the inflatable body. The pipetter according to claim 1, wherein the pipetting device is configured so that the outer expanding surface of the expanding body is in close contact with the inner peripheral surface of the pipette tip by injection. 5. An inner peripheral surface directed downward from an upper end opening of the pipette tip has a tapered shape with a gradually decreasing diameter, and an inflating body facing this inner peripheral surface is arranged to have a similar tapered shape. The pipettor according to any one of claims 1 to 4, wherein the pipettor is provided. 6. An outer periphery of the main body portion extends downward with a predetermined thickness to form a cylindrical portion, and an air passage forming portion of the main body portion extends downward to insert an insertion portion to be inserted into the cylindrical body portion. An inflatable body having an insertion hole through which the insertion portion is inserted at one end and an opening at the other end is inserted through the insertion hole through the insertion hole at one end, and the other end is inserted along the inner wall of the cylindrical body. Is fixed at the outer peripheral surface of the cylindrical body portion by turning the lower end side of the cylindrical body portion or folded back, and configured so that a fluid is injected between the cylindrical body portion and the inflatable body and the outer peripheral surface of the pipette tip is gripped by the inflatable body that inflates inward. The pipettor according to claim 1, wherein 7. The inflatable body is provided with a fixing plate provided in an insertion portion inserted into the insertion hole of the inflatable body, and fixed at one end side of the inflatable body between the lower surface of the main body and the fixed plate. The pipettor described in. 8. The pipetter according to claim 6, wherein a guide member is provided at a lower end of the cylindrical body portion to guide an upper end opening side of the pipette tip to guide the pipette tip to a space surrounded by an inflatable body. 9. The apparatus according to claim 1, wherein a thread is formed on an upper end side of the main body, and the male screw is screwed into a female screw of the main body so that a large number of main bodies can be attached to the main body. 9. The pipettor according to any one of 1 to 8. 10. An apparatus according to claim 1, wherein an elastic member is provided in place of the female screw of the main body device, and an upper end side of the main body portion can be inserted into the elastic member. Pipettor according to the item. 11. A body provided with an air passage for sucking air in the pipette tip or for sending air into the pipette tip at an upper end opening side of the pipette tip having a suction / discharge port for sucking / discharging the liquid at the tip. In the pipettor with the part attached, a plurality of air passages are formed in the main body part, a plurality of pipette tips are mounted, and an inflatable body that expands by injection of a fluid is attached to the main body part, separately from the air passage. The expanded body expanded by injecting a fluid from the fluid supply / discharge channel formed in the main body is brought into close contact with the inner peripheral surface or the outer peripheral surface of the upper end opening side of the pipette tip so that the pipette tip is gripped by the expanded body. A pipettor characterized by: 12. In a plurality of air passages formed in the main body, the air passage forming portion extends downward to form insertion portions to be inserted into the pipette tip, and tubes provided on the outer periphery of each of the insertion portions One end of the inflatable body is fixed or in contact with the outer periphery of the insertion portion, and the inflatable body is folded back from a predetermined length to form a superimposed portion, and the peripheral edge of the inflatable body is fixed to the lower surface of the main body, Most of the expansion body provided on the outer circumference of the insertion part is inserted into the pipette tip together with the insertion part, and fluid is injected into the space of the overlapping part of the expansion body to press the outer expansion surface of the expansion body against the inner peripheral surface of the pipette tip. The pipettor according to claim 11, wherein the pipetter is configured to perform the following. 13. A fixing plate having a hole through which an inflatable body provided on an outer periphery of the insertion portion and the insertion portion is provided in the main body,
A fluid passage for feeding the fluid injected from the flow path of the main body to the space of the overlapping portion of the expander is provided between the main body and the main body. 13. The pipettor according to claim 12, wherein the pipettor is formed between the expansion bodies. 14. The pipetter according to claim 12, wherein a guide member provided with a passage communicating with an air passage of the insertion portion is provided at a tip of the insertion portion. 15. An inner peripheral surface directed downward from an upper end opening of the pipette tip has a tapered shape whose diameter gradually decreases,
The pipettor according to any one of claims 11 to 14, wherein the expansion body facing the inner peripheral surface is also arranged to have a similar taper shape. 16. The pipettor according to claim 1, wherein a reinforcing cord is embedded in the expansion body.