JP2002204945A - Micropipet, dispenser, and method for producing biochip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micropipet used in fields such as the production of biochips such as DNA microarrays, to provide a dispenser, and to provide a method for producing a biochip. SOLUTION: In the micropipet 10, a port 2 that pours a specimen, a cavity 3 that holds the specimen, and a port 6 that delivers the sample to the external are formed on the pipette body 1; a piezoelectric/electrostrictive element 7 is formed on the external surface of the body 1; the volume of the cavity 3 is changed by driving the element 7; a definite amount of the specimen held in the cavity 3 is delivered from the port 6, and it is charaterized in that the shape of a cross section rectangular to the axial direction is a polygonal one having at least three protrusions radially protruding from the center and having interior angles including acute and obtuse angles or a crown one defined by a curve connecting the protrusions, the area of the cross section changes in a manner that it continuously and gradually decreases over the distance between the specimen inlet end 23 of a through-hole 5 and the specimen exit end 24 while it keeps approximately similar figures.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a biochip such as a micropipette, a pipetting device, and a DNA microarray. More specifically, a micro spot, which is preferably used in the field of manufacturing a biochip such as a DNA microarray, which involves an operation of aligning and fixing a small volume of liquid droplets on a predetermined substrate at a high density (a micro spot forming operation). TECHNICAL FIELD The present invention relates to a micropipette capable of achieving high definition in the forming operation of a micropipette and improving the obtained product quality, a dispensing apparatus using the micropipette, and a method for producing a biochip such as a DNA microarray.

[0002]

2. Description of the Related Art In recent years, methods for analyzing gene structures have been remarkably advanced, and many gene structures including human genes have been revealed. For analysis of such a gene structure, a DNA microarray in which thousands to tens of thousands of different types of DNA fragments are aligned and fixed as minute spots on a substrate such as a microscope slide glass is used.

As a method of forming minute spots in the production of this DNA microarray, a QUIILL method,
The pin & ring method or the spring pin method is widely used. Whichever method you choose,
By minimizing the variation in capacitance and shape of each minute spot,
It is required to keep the distance between the minute spots constant and prevent contamination due to intermixing, but in order to further increase the density in the future, further refinement of the work of forming minute spots and the products obtained There is an increasing demand for further improvement in quality.

[0004]

Problems to be Solved by the Invention Here, QUIILL
In this method, a sample is stored in a recess formed at the pin tip, and the sample in the recess is transferred onto the substrate by bringing the pin tip into contact with the substrate to form a minute spot. There is a problem that the sample stored in the recess is incompletely washed due to deformation or damage, and that the sample stored in the recess is incompletely liable to cause cross contamination.

In the pin & ring method, after a sample solution in a microplate is reserved by a ring, the solution penetrates the inside of the reserved ring, the sample in the ring is caught by a pin, and the sample is placed on a substrate. This is a method of forming spots. The sample that can be reserved at one time depends on the number of rings, and since the number is about several types in the past, small spots of thousands to tens of thousands of samples can be used. In order to form it, several hundred to several thousand washing and drying steps are also required, which is problematic in terms of productivity.

The spring pin method is a method of forming a minute spot by transferring a sample adhered to a pin tip onto a substrate by pressing the pin tip against the substrate, and has a double pin structure with a built-in spring. , Pins and substrates are softened and a sample is blown out, but basically only one spotting can be performed with one reserve, which still has a problem in productivity.

[0007] In these conventional methods for forming minute spots, all of the sample solutions are transported onto the substrate while being exposed to the atmosphere. Therefore, a problem occurs in that the sample dries during transportation and spotting cannot be performed. There are problems such as poor use efficiency of the sample solution.

A non-contact spotting method is a method for solving the problem of the above-described method for forming a minute spot. A micropipette using a piezoelectric / electrostrictive element as a micropump and a dispensing device using the same have been developed and put into practical use as a device for dispensing a minute amount of a biological sample with high accuracy using this method. . The non-contact spotting method involves discharging a biological sample containing nucleic acids, amino acids, and the like as fine droplets into the air and attaching the droplet onto a slide substrate. The problem is solved.

However, this method discharges minute droplets of a biological sample having a relatively high viscosity into the air and attaches them to the slide substrate. ), So-called satellites (splash-like droplets smaller than the target droplets) are generated and adhere to the substrate to form spots at locations other than the original spot formation positions, or to form small spots between spots. There was a problem in the quality of the resulting product, such as the inability to keep the distance constant, causing contamination due to intermixing. Such a so-called satellite does not occur in the early stage of the operation of the dispensing apparatus, but may occur after the operation for a while, which is a very troublesome problem in process management.

Further, when the discharge speed of the droplet is high, when the droplet adheres to the slide substrate, the force of the droplet is large, and the droplet (splash) is generated, and an unnecessary spot due to the droplet (also a satellite) is generated around the spot. Call). In order to prevent the occurrence of such a so-called satellite, the discharge speed may be reduced. However, when the discharge speed is reduced, the discharge becomes unstable.

Further, in order to increase the density of spot formation, it is necessary to always stabilize (straight) the ejection direction. For this reason, it is possible to reduce the variation in the ejection direction by shortening the distance between the ejection nozzle and the slide substrate. However, in addition to the variation in the thickness of the slide substrate itself, the mechanical There has been a problem that an increase in cost cannot be avoided in order to increase accuracy.

In addition, for example, many biological samples containing DNA and the like have high viscosity, and are required to have a property that, after being discharged and adhered, quickly dry so that spots do not spread on a slide substrate. When such a sample is used, there is a problem that the nozzle tends to be clogged and cannot be discharged because the nozzle is easily dried or thickened.

On the other hand, a method of spotting by diverting an ink jet system used for a printer is also being studied. For example, a nozzle hole for ejecting ink is formed in a shape having at least one corner, and an ink jet recording head utilizing the capillary force of this corner (Japanese Patent Laid-Open No.
9-178258). But,
The head disclosed in this publication exhibits a certain effect in preventing air bubbles from entering the nozzles, but can always sufficiently satisfy the above-mentioned problems such as prevention of so-called satellite generation. It was not something.

In addition, the shape of the sample ejection port is a 2n polygon having a symmetry (n is 3 or more), and the ink path has a trapezoidal cross section in the direction orthogonal to the ink ejection direction (particularly, an ink jet head). No. 3-101960). However, the head disclosed in this publication also exerts a certain effect in that the amount and the ejection speed of the ink droplets required for recording can be obtained stably, but the above-described so-called satellite Problems such as prevention of occurrence were not always satisfactory.

[0015] Furthermore, since the objects of the inventions disclosed in these publications are not mainly intended for spot formation of a biological sample, it is difficult to divert those disclosed in these publications as they are. There was a problem. That is,
Forming thousands to tens of thousands of samples in individual flow paths in such an ink jet recording head has many problems in terms of size and cost.Furthermore, in the ink jet method, a pump is previously installed in a pump before spotting. It is necessary to fill the sample without containing bubbles, and therefore, a large amount of the sample for purging is required, and there is a problem that the use efficiency of the sample is extremely poor. In general, it is more convenient for a liquid to move at a high speed in a flow path including a pump chamber to remove bubbles. However, when a biological sample, for example, a delicate DNA solution is used, In such a case, there was a problem that the DNA was damaged.

The present invention has been made in view of the above-described problem, and involves a work (work of forming a minute spot) in which a small volume of liquid droplets is aligned and fixed on a predetermined substrate at a high density.
A micropipette, which is preferably used in the field of production of biochips such as NA microarrays, capable of forming fine spots with high definition and capable of improving the product quality obtained, using this micropipette It is an object to provide a dispensing device and a method for producing a biochip.

[0017]

According to the present invention, there is provided the following micropipette, a dispensing apparatus using the micropipette, and a method for producing a biochip.

[1] A sample injection port for injecting a sample from the outside of the pipette body, a cavity capable of introducing and temporarily storing the injected sample, and a through hole of the nozzle portion for transferring the stored sample to the pipette body. And a sample discharge port to be discharged to the outside via a piezoelectric / electrostrictive element provided on the outer surface of a portion corresponding to the cavity forming position of the pipette body, and driven by the piezoelectric / electrostrictive element. A micropipette that changes the volume in the cavity and discharges a certain amount of the sample stored in the cavity from the sample discharge port, and the through-hole in the nozzle portion has a cross-sectional shape perpendicular to the axial direction, It has three or more projections radially protruding from the center, and has a polygonal shape having an inner angle of an acute angle and an obtuse angle or a crown shape in which a projection and a projection are connected by a curve, and A micropipette characterized in that the area (cross-sectional area) of the cross-sectional shape changes from the sample introduction port end to the sample discharge port end of the through-hole so as to decrease gradually while maintaining a substantially similar shape.

[2] A sample injection port for injecting a sample from the outside of the pipette body, a cavity for introducing and temporarily storing the injected sample, and a through hole of a nozzle portion for transferring the stored sample to the pipette body. And a sample discharge port to be discharged to the outside via a piezoelectric / electrostrictive element provided on the outer surface of a portion corresponding to the cavity forming position of the pipette body, and driven by the piezoelectric / electrostrictive element. A micropipette that changes the volume in the cavity and discharges a certain amount of the sample stored in the cavity from the sample discharge port, and the through-hole in the nozzle portion has a cross-sectional shape perpendicular to the axial direction, The through hole has a substantially circular shape from the end of the sample inlet to the first point at a predetermined distance from the end of the sample outlet, and at the end of the sample outlet, three or more protrusions projecting radially from the center. It has a polygonal shape having an acute angle and an obtuse angle, or a crown shape formed by connecting projections with a curve, and has an area (cross-sectional area) of a cross-sectional shape thereof.
However, the micropipette is characterized in that the through hole changes from the end of the through hole to the first point, while maintaining a substantially circular shape, while continuously decreasing to the end of the sample outlet.

[3] The polygonal shape or the crown shape having the protrusions according to the above [1] or [2], wherein an angle formed by a straight line connecting an apex of the adjacent protrusion and the center is 1 to 120 degrees. The described micropipette.

[4] The above-mentioned [1] to [3], wherein the total length of the polygonal or crown-shaped sides having the protrusions is 1.1 times or more the circumference of a circle having the same area. The micropipette according to any one of the above.

[5] The continuously decreasing rate of change of the cross-sectional area of the through-hole in the nozzle portion is from a sample introduction port end of the through-hole to a second point at a predetermined distance from the sample discharge port end. The micropipette according to any one of [1] to [4], wherein the rate of change from the second point to the end of the sample outlet is larger than the rate of change of.

[6] The nozzle according to any one of [1] to [5], wherein a surface roughness of an inner surface of the through-hole in the nozzle portion is rougher than that of a surface of the through-hole on which a sample inlet end is formed. Micropipette.

[7] The micropipette according to any one of [1] to [6], wherein the surface of the through hole in the nozzle portion near the end of the sample outlet is subjected to a liquid repellent treatment.

[8] The micropipette according to any one of [1] to [7], wherein at least a portion of the pipette body corresponding to the cavity forming position and the piezoelectric / electrostrictive element setting position is made of zirconia ceramics.

[9] The zirconia ceramics is:
The micropipette according to the above [8], which is manufactured by using a green sheet laminating and firing method.

[10] The above-mentioned [1] to [9] in which the portion of the pipette body where the sample discharge port is formed is made of resin.
The micropipette according to any one of the above.

[11] The piezoelectric / electrostrictive element comprises a piezoelectric / electrostrictive film containing as a main component at least one lead compound selected from the group consisting of lead zirconate, lead titanate and lead magnesium niobate. The above [1] to constituted
The micropipette according to any one of [10].

[12] A plurality of the sample injection ports, a plurality of the cavities, and a plurality of the sample discharge ports are formed in one pipette body.
The micropipette according to any one of 1).

[13] The pipette body is composed of a plurality of first pipette members and one second pipette member, and the first pipette member has the cavity and the piezoelectric / electrostrictive element formed therein. A plurality of sample injection ports and a plurality of sample discharge ports are formed in the second pipette member, and the plurality of first pipette members and one of the second pipette members are joined to each other. The micropipette according to any one of the above [1] to [11].

[14] The pipette according to any one of [1] to [13], wherein the pipette body is formed of a flat plate, and a sample discharge port is formed on a side surface or a main plane of the pipette body. Micro pipette.

[15] The pipette body is formed of a flat plate, the sample discharge port is formed on one main plane of the pipette body, and the sample injection port is formed on the other main plane. The micropipette according to any one of [1] to [13].

[16] The above [1] to [15], wherein a plurality of the sample injection ports are connected to one cavity.
The micropipette according to any one of the above.

[17] A micropipette complex, wherein a plurality of the micropipette according to any one of [1] to [16] are fixed to a fixing jig.

[18] A dispensing device comprising a plurality of micropipettes according to any one of [1] to [16] or one or more micropipette complexes according to [17], A dispensing apparatus characterized in that sample outlets formed in the pipette main body are arranged vertically and horizontally and different liquid samples are respectively discharged from these sample outlets.

[19] In each of the sample injection ports,
The dispensing device according to [18], further including a first cartridge separately filled with different kinds of liquid samples, and capable of discharging different kinds of samples from the sample discharge ports.

[20] At each of the sample injection ports,
[18] comprising a second cartridge filled with an aqueous solvent or an organic solvent, and capable of washing a communication space from a sample injection port to a sample discharge port formed in the pipette body.
Or the dispensing device according to [19].

[21] The above-mentioned [18] wherein an anisotropic flying-drop shielding plate made of a thin plate having an opening coaxial with the central axis of the sample outlet is provided outside each of the sample outlets formed in the pipette body. ]-The dispensing apparatus in any one of [20].

[22] The micropipette according to any one of [1] to [16], the micropipette complex according to [17], or the micropipette according to any of [18] to [21]. A method for producing a biochip, comprising using a dispensing device.

[0040]

Embodiments of the present invention will be specifically described below with reference to the drawings. I. Micropipette As shown in FIG. 1A, the micropipette 1 of the present invention
Reference numeral 0 denotes a sample injection port 2 for injecting a sample from the outside of the pipette body 1 into the pipette body 1, a cavity 3 for introducing and temporarily storing the injected sample, and passing the stored sample through the nozzle unit 4. A sample discharge port 6 for discharging to the outside via the hole 5 is formed, and a piezoelectric / electrostrictive element 7 is provided on an outer surface of a portion of the pipette body 1 corresponding to a position where the cavity 3 is formed. The micropipette 10 changes the volume in the cavity 3 by driving the electrostriction element 7 and discharges a fixed amount of the sample stored in the cavity 3 from the sample discharge port 6.

Specifically, in the nozzle unit 4, a thin flat plate-shaped nozzle plate 11 provided with a sample discharge port 6 including one or more through holes 5 can be formed of a PET resin sheet. In addition, the nozzle part 4 (through-hole 5) is usually
It may be formed by machining such as punching of a mold, but if the material is a resin such as PET or polyimide,
Laser (eg, excimer laser, high-order (third or higher) YAG laser) processing can be preferably used. To form a cross-sectional shape in a direction perpendicular to the axial direction of the through hole, a laser beam is moved along the shape, a so-called beam scanning method or a mask in which a similar shape of the cross-sectional shape is formed in the middle of the laser irradiation axis. A so-called mask method for setting can be used. Among them, a mask method in which a large number of through holes can be simultaneously formed is preferable. on the other hand,
The pump unit 12 includes a spacer plate 14 having one or more windows 13 formed thereon, and a closing plate 15 that covers the windows 13 by being overlapped on one side of the spacer plate 14.
Are formed of green sheets of zirconia ceramics, and the whole is laminated and fired integrally to form the pipette body 1. The closing plate 15
Is provided with a sample injection port 2, which is connected to an introduction hole 16 and a communication path 17 connected to a window 13 formed in a spacer plate 14. Then, on the outer surface of the closing plate 15, there can be cited one in which the piezoelectric / electrostrictive element 7 including the lower electrode 20, the piezoelectric / electrostrictive film 19 and the upper electrode 18 is formed.

According to the micropipette configured as described above, when an electric field is generated between the upper electrode 18 and the lower electrode 20, the piezoelectric / electrostrictive element 7 is deformed and the window 13 is covered. When the volume of the cavity (pressurized chamber) 3 is reduced, the sample (DN
DNA containing fragment A) is discharged from the sample discharge port 6 communicating with the cavity 3 at a predetermined speed, and is aligned and fixed as a minute spot on a substrate such as a microscope slide glass.
A biochip such as a microarray can be manufactured. Incidentally, a device structure of a so-called ink jet system as shown in FIGS.
No. 40030.

In the micropipette having the above-described configuration, it is preferable that the cavity (pressurizing chamber) 3 is formed in a shape and a flow path dimension such that a liquid sample containing a DNA fragment or the like moves in a laminar flow. .

FIG. 1 shows an example of a specific cavity.
A description will be given according to (c). The shape of the cavity 3 is shown in FIG.
As shown in (c), the sample injection port 2 or the introduction hole 22 for introducing a sample is provided in one end of a long shape, and the sample discharge port 6 is connected to the other end. With such a shape, the cavity 3 is used as a part of the flow path from the sample injection port 2 to the sample discharge port 6, and the communication path 21 and the introduction hole 22 from the sample injection port 2 or from the sample injection port 2 are formed. The sample flowing through the cavity 3 through the cavity 3 can be guided to the sample discharge port 6 without being disturbed. The specific dimensions of the cavity 3 vary depending on the type of sample, the size of a droplet to be prepared, and the formation density. For example, a DNA fragment having a base pair length of 1 to 10,000 bp at a concentration of 1 μg / μl in × 1 TE buffer ( 10 mM T
DNA that requires spotting of a sample dispersed in ris-HCl (pH 8.0) 1 mM EDTA) at a pitch of several hundreds of microns and a droplet diameter of several tens to several hundreds of microns [phi].
In the case of a micropipette for producing a biochip such as a microarray, the cavity length (L) is 1 to 5 mm, the cavity width (W) is 0.1 to 1 mm, and the cavity depth (D) is 0.1 to 1 mm. 0.5 mm is preferred. The inner wall of the cavity is preferably smooth so that there are no protrusions that disturb the flow, and its material is preferably made of ceramics having a good affinity for the sample solution.

By configuring the present invention as described above,
A minute amount of liquid is ejected from the sample ejection port in response to each drive of the piezoelectric / electrostrictive element, and the volume can be made minute and constant without variation. The driving cycle is
By using the piezoelectric / electrostrictive element, it becomes possible to cope with a high frequency, and the time required for ejection can be reduced. In addition, since the sample moves in the closed space until the ejection after the sample injection, the sample does not dry on the way. Furthermore, since the entire pipette body can be formed small and compact, the flow path through which the sample moves can be shortened, and it is possible to prevent the sample from adhering to the flow path wall and deteriorating the use efficiency. .

In the micropipette of the present invention,
The cavity is previously filled with a replacement liquid such as a buffer solution or physiological saline, and then the sample is injected from the sample introduction hole into the cavity while undergoing laminar flow displacement, and the piezoelectric / electrostrictive element is driven to drive the sample in the cavity. May be discharged from the sample discharge port. The end point of the completion of the laminar flow replacement may be determined in advance by determining the moving speed and volume of the sample and controlling the replacement time, but it is more preferable to grasp the end point by detecting a change in the fluid property in the cavity. The sample may be subjected to laminar flow displacement from the sample introduction hole into the cavity while driving the piezoelectric / electrostrictive element. After reliably replacing the inside of the cavity with an inexpensive replacement liquid in advance, laminar flow replacement of the expensive sample can completely prevent the occurrence of ejection failure and efficiently discharge the expensive sample. Further, in the micropipette of the present invention, the cavity is filled with a replacement solution such as a buffer solution or physiological saline in advance, and then the sample is injected while being replaced from the sample introduction hole into the cavity, and the end point of the replacement completion is determined. ,
After grasping by detecting a change in the fluid characteristic in the cavity, it is preferable to drive the piezoelectric / electrostrictive element to discharge the sample in the cavity from the sample discharge port. By grasping the completion of replacement by detecting a change in the fluid properties in the cavity, even if the sample and the replacement liquid mix somewhat in the flow path, it is possible to distinguish between the mixed part and the unmixed part. Since it can be performed easily and accurately, the amount of the sample that must be purged by mixing with the replacement liquid can be reduced, and the use efficiency of the sample can be increased.

Further, it is preferable that the change in the fluid characteristic in the cavity is grasped by applying a voltage for exciting vibration to the piezoelectric / electrostrictive element and detecting a change in an electric constant accompanying the vibration. By doing so, it is not necessary to install a special detection element or the like, and it is possible to perform inexpensive and highly accurate detection.

As shown in FIG. 2, the area (cross-sectional area) of the cross-sectional shape of the nozzle portion of the micropipette of the present invention in the direction perpendicular to the axial direction of the through-hole 5 is measured from the sample introduction port end 23 of the through-hole. The sample discharge port end 24 is configured to change continuously so as to gradually decrease while maintaining a substantially similar shape. That is, the cross-sectional area at the sample inlet end 23 is, for example, continuous through the cross-sectional area along the line BB and the cross-sectional area along the line CC shown in FIG. Decrease gradually. With this configuration, the flow of the sample that has been disturbed at the sample introduction port end 23 (the flow velocity of the sample varies within the same cross section) can be rectified before reaching the sample discharge port end 24. Therefore, the discharge direction can be stabilized, the flow rate of the sample at the sample outlet end 24 can be efficiently increased, and the breakage of droplets during discharge is improved. Can be prevented.

As shown in FIGS. 3A, 3B and 4, a cross section in a direction perpendicular to the axial direction of the through hole (for example,
2 is a polygonal shape having three or more projections 8 projecting radially from the center O and having an acute angle and an obtuse angle, or a crown shape connecting the projections and the projections with a curved line. It is configured to be. With such a configuration, the droplet discharged to the outside from the sample outlet end 24 has a shape having a protrusion corresponding to the shape of the through-hole 5 immediately after the discharge, and immediately has a surface tension. In this case, the cutoff of the droplet discharged from the through-hole 5 of the nozzle portion is improved (it quickly becomes one droplet) by the action of the surface tension, and the rear portion of the droplet The generation of so-called satellites in which droplets are finely separated can be prevented. In addition, since the flow of the sample can be rectified by the protrusion 8, the ejection direction can be stabilized. The gradual reduction of the cross-sectional area of the through-hole 5 and the setting of the predetermined shape, which are effective for improving the stability of the ejection direction and preventing the generation of satellites, are effective even if they are performed independently. It will have a remarkable effect. By the way, FIG.
The projection shape of the polygonal shape or the crown shape shown in (b) does not necessarily have to be a sharp shape as shown in the figure, but depends on the material of the nozzle portion, the processing method, and the accuracy of the processing machine.
The tip may be blunt.

As shown in FIG. 5A, FIG. 5B and FIG. 6, the micropipette of the present invention is such that the cross-sectional shape of the through hole 5 in the nozzle portion in the direction perpendicular to the axial direction is A first point (shown by a line DD in FIG. 5) that is separated from the sample inlet end 23 by a predetermined distance toward the sample outlet end 24 is substantially circular and has a first point (line DD). ) To the sample outlet end 24 have three or more projections 8 protruding radially from the center, and have a polygonal shape having an acute angle and an obtuse angle or a crown shape in which the projections and the projections are connected by a curve ( (See FIGS. 3A and 3B.) In addition, the area (cross-sectional area) of the cross-sectional shape is substantially circular from the sample introduction port end 23 of the through hole to the first point (DD line). The configuration may be such that the pressure gradually decreases continuously to the sample outlet end 24 while performing the above operation. Here, the range of the first point is intermediate between the sample inlet end 23 and the sample outlet end 24, and when the distance from the sample inlet end 23 to the sample outlet end 24 is 1, From the sample inlet end 23, 0.1 to
0.7 is preferred. If it is less than 0.1, the cross-sectional shape (circle) of the sample introduction port end 23 may not be formed stably. On the other hand, when it exceeds 0.7, the rectifying effect of the projection shape may be insufficient. With this configuration, as described above, the cut of the droplet discharged from the through-hole of the nozzle portion is improved due to the protrusion shape at the sample outlet end 24 (the one droplet is quickly removed). Therefore, it is possible to prevent generation of a so-called satellite in which the droplet is finely separated at the rear portion of the droplet. Further, since the sample inlet end 23 has a substantially circular shape, the pressure from the cavity and the flow of the sample are uniformly transmitted to the nozzle portion, and the rectification due to the projection shape from the first point to the sample outlet end 24. The effect can stabilize the ejection direction on the sample.

Further, in the micropipette of the present invention, as shown in FIG. 3, a straight line connecting the apex (for example, P, Q) of the adjacent protrusion 8 and the center O of the polygon having the protrusion 8 is formed. Is preferably 1 to 120 degrees, more preferably 3 to 72 degrees. If this angle is less than 1 degree, the angle approximates a circle, and the effect of the present invention may not be sufficiently exhibited. Also,
If it exceeds 120 degrees, the ejection direction of the sample may become unstable.

In the micropipette of the present invention, as shown in FIG. 3, the total length L1 of the polygonal or crown-shaped sides having the projections 8 is the circumferential length L2 of a circle having the same area as this. It is preferably 1.1 times or more (L1 / L2 ≧ 1.1), and more preferably 1.15 times or more. If the ratio is less than 1.1 times, the sample may be approximated to a circle and a so-called satellite may be generated. In addition, the sample may be dried near the discharge port end 24 of the nozzle portion, causing a discharge defect or a discharge bend. There is.

Further, in the micropipette of the present invention, as shown in FIG. 2 and FIGS. 5A and 5B, the rate of change of the cross-sectional area of the through hole 5 in the nozzle portion that continuously decreases gradually is as follows. From the sample inlet end 23 of the through hole to the sample outlet end 2
The sample discharge end from the second point (the EE line and the FF line) is smaller than the rate of change up to the second point (the EE line and the FF line) which is separated by a predetermined distance toward the fourth point. It is preferable to configure so that the rate of change up to 24 is larger. By thus narrowing the sample toward the sample outlet end 24 in two steps, the effect of rectifying the sample can be further improved, and the efficiency of improving the sample flow velocity at the sample outlet end 24 can be increased. Here, the range of the second point is intermediate between the sample inlet end 23 and the sample outlet end 24, and when the distance from the sample inlet end 23 to the sample outlet end 24 is 1, From the sample inlet end 23, 0.3 to
0.7 is preferred. The second point is shown in FIG.
As shown in (b), matching with the first point
It is preferable from the viewpoint of preventing generation of satellite and rectifying effect, and also facilitates formation of a through hole including the sample introduction port end 23 and the sample discharge port end 24. The material of the nozzle member is PET,
In the case of a resin such as polyimide, laser (for example, excimer laser, high-order (third or higher) YAG laser) processing can be preferably used. What should be done is to change the power of the laser. That is, when the rate of change from the sample inlet end 23 to the second point is smaller than that from the second point to the sample outlet end 24 as shown in FIGS. The laser irradiation may be performed from the sample introduction port end 23, and the laser power may be reduced during the processing.

When the cross-sectional area of the through-hole is gradually reduced, the gradual reduction rate of the axial cross-sectional shape of the through-hole, such as the spindle shape shown in FIG.
The shape may be a shape that is continuously increased toward 4, and in that case, for example, a method in which laser irradiation is performed from the sample introduction port end 23 and the power is continuously reduced is employed.

Further, in the micropipette of the present invention, as shown in FIG. 1, the surface roughness of the inner surface of the through hole 5 in the nozzle portion is smaller than the surface 38 of the through hole 5 where the sample inlet end 23 is formed. It is preferable to make it coarser. Since the surface roughness of the inner surface of the through hole 5 is rougher than that of the other portions, the through hole 5 after the sample has been discharged is finished.
Fluctuation (vibration) of the liquid surface of the sample remaining inside
Because of the convergence, it is possible to prevent the generation of satellite due to the remaining liquid level.

Further, in the micropipette of the present invention, it is preferable that the surface of the through hole in the nozzle portion near the end of the sample outlet is subjected to a liquid repellent treatment. By increasing the water repellency of the surface of the through-hole near the end of the sample discharge port and synergistic effects with other configurations, the breakage of the droplet can be further improved.

In the micropipette of the present invention, it is preferable that at least a portion of the pipette body corresponding to the cavity forming position and the piezoelectric / electrostrictive element setting position is made of zirconia ceramics. It is more preferable that all parts are made of zirconia ceramics. In this case, the zirconia ceramic is preferably manufactured using a green sheet lamination firing method.
Zirconia, in particular, stabilized zirconia and partially stabilized zirconia, have a large mechanical strength even as a thin plate,
It is excellent as a material for the pipette body used in the present invention because of its high toughness, durability in an acid / alkali solution, and low reactivity with a piezoelectric film and an electrode material.

Further, the portion of the pipette body where the sample discharge port is formed may be made of resin from the viewpoint of moldability and cost.

Further, the piezoelectric / electrostrictive element used in the present invention is a piezoelectric / electrostrictive element containing, as a main component, at least one lead compound selected from the group consisting of lead zirconate, lead titanate and lead magnesium niobate. It is preferable to be composed of a strain film. That is, such a piezoelectric / electrostrictive film is
A pipette body (zirconia ceramics) that has a high electromechanical mechanical coupling coefficient and piezoelectric constant when sintering a piezoelectric film
Is preferred since it has a low reactivity with and a stable composition can be obtained.

Further, in the micropipette of the present invention, as shown in FIG.
A plurality of sample injection ports 2, cavities 3, sample discharge ports 6, and piezoelectric / electrostrictive elements 7 were formed at a plurality of locations, respectively, and the upper electrode 18 and the lower electrode 20 of each piezoelectric / electrostrictive element 7 were collectively pulled out. It may be something. With this configuration, it is possible to arrange the sample ejection ports with high precision and high density, and to simultaneously eject different kinds of samples, so that a biochip such as a DNA microarray can be used. It can be efficiently manufactured with high productivity.

Also, the micropipette of the present invention may comprise one or more first and second cavities and a piezoelectric / electrostrictive element.
One or more joined bodies obtained by joining one or more second pipette members forming one or more of at least one of a sample injection port and a sample discharge port. It may be fixed and integrated. Specifically, as shown in FIG.
A first pipette member 1c in which one electrostrictive element 7 and one introduction hole 35 are formed, a second pipette member 1a in which one sample injection port 2 and one communication path 36 are formed, and a sample. After separately forming a second pipette member 1b in which a plurality of discharge ports 6 are formed, an adhesive 3
7 can be used. As each material, for example, the first pipette member 1
c is partially stabilized zirconia, second pipette member 1a
Is partially stabilized zirconia, and the second pipette member 1b is P
One made of ET resin can be mentioned. The joining with each other may be performed mechanically, but joining with an adhesive or heat diffusion is preferable from the viewpoint of maintaining the sealing property of the flow path. With this configuration, it is possible to expand the range of material selection for the pipette body and to select the most suitable material for each part, while improving the yield of elements, high precision of the sample discharge ports, high-density arrangement, Simultaneous ejection of a plurality of types of samples becomes possible.

As shown in FIGS. 9A and 9B, the micropipette of the present invention may be a so-called edge type. That is, a plurality of sample injection ports 2, cavities 3, sample discharge ports 6, and piezoelectric / electrostrictive elements 7 are formed in one pipette body 1 respectively. In this micropipette, the sample outlet 6 is formed on the side surface of the pipette main body 1, and the sample injected from the ordinary pipette 25 into the sample inlet 2 passes through the communication passage 26 in the pipette main body 1. The volume of the sample flowing into the cavity 3 is changed by driving the piezoelectric / electrostrictive element 7, and a certain amount of the sample filled in the cavity 3 is discharged from the sample discharge port 6. . When the sample outlet 6 is formed on the side surface of the pipette body 1, the density of the sample outlet 6 can be easily increased by arranging the flat pipette bodies 1 vertically.

As shown in FIGS. 10A and 10B, the micropipette of the present invention
(B), FIGS. 11 (a) to (d) and FIG. 12 (a),
Similar to FIG. 9 (b), this is a so-called face type. As in FIGS. 9 (a) and 9 (b), a sample injection port 2, a cavity 3, a sample discharge port 6, And a plurality of piezoelectric / electrostrictive elements 7 may be formed. In this micropipette, the sample discharge port 6 is formed on the main plane of the pipette body 1. Between the cavity 3 and the sample inlet 2
They are connected by an introduction hole 27 and a communication passage 28. And
A sample inlet 2 is formed on the other main plane. In such a configuration, the ejection port can be formed more easily and accurately than the edge type, and when the sample ejection port 6 is formed on the main plane of the pipette body 1, it is parallel to the flat plate on which the sample ejection port 6 is formed. Then, the substrate can be set, and the discharge distance of the droplets can be easily made constant, and the shape of the droplets can be stabilized. Further, by forming the sample inlet 2 and the sample outlet 6 on different main planes of the pipette body 1, respectively, the length of the flow path from the sample inlet 2 to the sample outlet 6 is almost equal to the thickness of the flat plate. Only, the flow path of the sample liquid is short and simple, bubbles can be caught in the middle of the flow path, and problems such as ejection failure can be reduced, and the sample use efficiency is further improved. be able to.

The micropipette of the present invention has a pipette body formed of a flat plate and a sample discharge port formed on a side surface or a main plane of the pipette body. By making the pipette body flat, the pipette body can be manufactured by laminating green sheets and the like as described later, and the whole can be made thin and compact. Further, as shown in FIG. 13, the pipette main body 1 is formed in a flat plate shape, the sample discharge port 6 is formed on one main plane of the pipette main body 1, and the sample injection port 2 is formed on the other main plane. The distortion element 7 may be formed in the same main plane as the sample discharge port 6. In this case, since the surface other than the sample inlet 2 is not formed on the surface where the sample inlet 2 is formed, there is an advantage that the sample can be easily injected.

The micropipette of the present invention may be a micropipette complex in which a plurality of the micropipettes (units) are fixed to a fixing jig. For example, as shown in FIG. 11, a unit in which one sample injection port 2, cavity 3, sample discharge port 6, and one piezoelectric / electrostrictive element 7 are formed in one pipette body 1 (FIG. An example is shown in which a plurality of (c) and (d)) are fixed to a fixing jig 29 (a generic name of a holding jig 30, a positioning pin 31, and a fixing plate 32 described later). Each unit includes a holding jig 30 for holding a tube (communication passage) 33 for supplying a sample to the sample inlet 2 and a positioning pin 31.
And is fixed to the fixing plate 32. In addition, FIG.
In (b), the fixing is performed by tightening both ends of the holding jig 30 to the fixing plate 32 with the screws 34, but the fixing method is performed mechanically with screws, springs, or the like, or with an adhesive or the like. Good. With this configuration, it is easy to manufacture each pipette body, and the yield can be improved.

Further, the micropipette complex of the present invention may be one in which a plurality of sample injection ports are connected to one cavity. Specifically, as shown in FIG. 14, an example in which two sample injection ports 2 are connected to one cavity 3 can be given. In this example, the piezoelectric / electrostrictive element 7 is formed in the same main plane as the sample inlet 2, and the sample outlet 6 is formed in the other main plane. With this configuration, the cavity can be reliably filled by adjusting the timing of the sample or the replacement liquid from the plurality of sample inlets, and sucking and pushing the same.

II. Dispensing device The dispensing device of the present invention includes a plurality of the micropipettes or one or more of the micropipette composites, and arranges sample discharge ports formed in the pipette main body vertically and horizontally and arranges these sample discharge ports. It is characterized in that different liquid samples are respectively discharged. With this configuration, many types of samples can be simultaneously supplied at a time, and a pipette partially defective can be easily replaced. Further, since the sample ejection ports are arranged vertically and horizontally, it can be suitably applied to a case where minute spots that are two-dimensionally aligned and fixed are required, such as a biochip such as a DNA microarray.

Specifically, as shown in FIG. 15, the dispensing device 55 of the present invention comprises a micropipette 50 having a sample inlet 52 and a sample outlet 51 shown in FIGS. 16A and 16B. A plurality (50a, 50b, 50c) may be formed by standing upright with the sample sample discharge port facing downward. That is, each micropipette 5
0a, 50b, and 50c are the respective sample injection ports 52.
a, 52b, and 52c are set to the upper side, and the sample discharge ports 51a,
1b, 51c are set to the lower side, and the sample discharge ports 51a,
51b and 51c are arranged vertically and horizontally, and the sample discharge port 5
Different types of liquid samples are ejected from 1a, 51b, and 51c, respectively. In addition, an anisotropic flying drop shielding plate 53 made of a thin plate having an opening coaxial with the central axis of the sample ejection port is provided outside each of the sample ejection ports 51a, 51b, 51c formed in the pipette body. Is also good. With the configuration including the anisotropic flying droplet shielding plate 53, even if the ejection direction of the ejection droplet is bent, the droplet does not reach the substrate,
It is possible to prevent a spotting misalignment and a defect that is mixed with an adjacent spot.

In the dispensing device 55 having such a configuration, as shown in FIG.
Each of the sample cartridges 2b and 52c is provided with a first cartridge 60 separately filled with a different kind of liquid sample, and is configured to be able to eject different kinds of liquid samples from the sample ejection ports 51a, 51b and 51c. This is preferable in that it can increase the use efficiency.

Further, each of the sample inlets is filled with an aqueous solvent (for example, physiological saline) or an organic solvent.
And a cartridge capable of cleaning the communication space from the sample injection port to the sample discharge port formed in the pipette main body.
This is preferable because it can discharge NA fragments and the like into minute spots without contamination and with high purity. The method of injecting a sample or the like from the cartridge into each of the sample inlets is to set the cartridge in the sample inlet and then open the bottom of the cartridge with a needle or the like. And may be opened simultaneously with the setting. Further, a mechanism may be added in which gas or the like is pressure-fed after opening and the sample or the like is forcibly pushed out.

III. Method for Producing Biochip A method for producing a biochip such as a DNA microarray according to the present invention is characterized by using the above dispensing device. Generally, a sample containing a DNA fragment spotted on a DNA microarray is placed in the first cartridge 60 shown in FIG.
In the case of using the dispensing device of the present invention using the micropipette of the present invention having a certain space in the pipette body, amplification is performed in the micropipette. May go.

As a method for producing a biochip of the present invention, for example, in the case of a DNA microarray, the following method can be mentioned. When the DNA fragment is amplified and used in the first cartridge 60, a cartridge containing a buffer solution as a replacement solution is set in advance, and the cavity in each micropipette is filled with the buffer solution. A cartridge containing a DNA fragment sample is set therein, the bottom of the cartridge is opened with a needle or the like, and the sample is injected into the sample injection port. Thereafter, the piezoelectric / electrostrictive element is driven to discharge laminar flow in the cavity with the sample while discharging the buffer solution previously filled from the sample discharge port. The end point of the replacement may be determined based on the volume of the discharged buffer, but is sensed by switching the relay so that the piezoelectric / electrostrictive element acts as a sensor for detecting the viscosity and specific gravity of the liquid in the cavity. After completion of the replacement, the DNA microarray is manufactured by driving the piezoelectric / electrostrictive element under the driving conditions corresponding to the amount of the droplet corresponding to the required spot diameter and repeating spotting. Usually, one to several hundred drops are ejected from a micropipette to form one spot.
When the amount of the sample in the sample inlet decreases, the sample can be used up without remaining in the micropipette by adding a buffer solution to prevent air bubbles from entering the flow path and continuing ejection. Completion of the replacement of the sample with the replacement liquid (end of discharge of the sample) is similarly performed by detecting the viscosity and specific gravity of the liquid using a piezoelectric / electrostrictive element. Further, a method of drying the solvent while forming microdroplets on a substrate using a sample solution whose concentration has been diluted in advance is also suitable. By performing such a method, the amount of the sample remaining in the flow channel can be further reduced, and the use efficiency of the sample can be improved. Further, it is preferable to use a replacement liquid and a sample to be used in which the dissolved gas in the solution has been removed through a deaeration operation in advance. By using such a solution, even when bubbles are caught in the middle of the flow channel when filling the solution into the flow channel and filling is incomplete, the bubbles are dissolved in the solution to avoid problems. In addition to the above, it is possible to prevent bubbles from being generated in the fluid during the discharge, thereby causing a problem related to the discharge.

[0073]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to Examples, but the present invention is not limited by these Examples. The embodiment shown in FIG.
A sheet made of a PET resin having a thickness of 38 μm was formed as a nozzle member, and through holes were formed using an excimer laser as a processing method. To form the cross-sectional shape in a direction perpendicular to the axial direction of the through-hole, a so-called mask method was used in which a mask previously formed in a similar shape to the cross-sectional shape was set in the middle of the laser irradiation axis. Laser irradiation is performed in the direction from the sample introduction port end 23 side of the through hole to the discharge port end 24 side, and the shape of the through hole at the sample introduction port end 23 is, as shown in FIG. The mask was designed such that the tangent diameter L4 was 75 μm, the angle θ formed by a straight line connecting the apex and the center of the adjacent protrusion was 15 degrees, and the linear distance L3 of the protrusion 8 was 13 μm. In order to form the cross-sectional shape in the direction parallel to the axial direction of the through hole so as to form a tapered shape toward the end of the sample outlet, the laser power was adjusted using a mask method. That is, the power of the laser is set to a value (30) at which a through hole is formed in a few seconds by laser irradiation.
mJ / sec), and processing was carried out over time. Specifically, the laser power was set to 20 mJ / sec, and the tapered shape was formed by adjusting so that a through hole could be formed over 20 sec. Then, as shown in FIG. 3A, the shape of the through hole at the sample discharge end 24 is a straight line connecting the apex of the adjacent protrusion and the center with the inscribed circle diameter L4 of the protrusion being 50 μm. Angle θ is 15 degrees,
The linear distance L3 between the projections was set to 8 μm. In addition, in the case of the embodiment shown in FIG.
It was prepared by a mask method using a circular mask. The laser power at that time was set lower than the above conditions, so that the sample inlet end 23 had a substantially circular shape and the sample outlet end 24 had a projection. Specifically, laser power 1
By setting 0 mJ and irradiation time of 20 sec, a circular shape having a diameter of 80 μm at the sample inlet end 23 of the through hole and a projecting inscribed circle diameter L4 at the sample outlet end 24 as shown in FIG. Is 50 μm, the angle θ formed by a straight line connecting the apex of the adjacent protrusion and the center is 15 degrees, and the linear distance L3 of the protrusion 8 is 8 μm. A sample in which a DNA fragment having a base pair length of 1000 bp was dissolved in a × 1 TE buffer (buffer solution) at a concentration of 1 μg / μl using a micropipette using a nozzle having a through hole shown in FIGS. In this case, no so-called satellite was generated even after discharging 100,000 times. In addition, the nozzle did not dry out during the series of discharging operations and became undischargeable, and the good discharging performance did not change even when the discharging interval was extended to 10 seconds or more. Also, in order to prevent the ejection speed from being too fast and causing the droplets to have a large momentum when adhering to the slide substrate and generating a splash, the deformation speed of the piezoelectric / electrostrictive element is reduced, and the ejection speed of the droplets is reduced. Reduced to less than half of conventional (4 m / sec)
In the case of (1) below, no satellite was generated, and no ejection instability such as bending of the ejection direction occurred.

[0074]

As described above, according to the present invention, in the field of the manufacture of DNA microarrays and the like, which involves an operation of aligning and fixing a minute volume of liquid droplets on a predetermined substrate at a high density (an operation of forming a minute spot). Provided are a micropipette, which is preferably used, which enables a high-definition formation operation of a minute spot and can improve the quality of the obtained product, a dispensing apparatus using the micropipette, and a method for producing a biochip. be able to. Therefore, according to the dispensing apparatus using such a micropipette and the method for manufacturing a biochip using such a dispensing apparatus, hundreds to tens of thousands of different kinds of samples can be efficiently dispensed at one time to obtain a minute spot. Can be formed, and productivity such as biochip production can be dramatically improved.

[Brief description of the drawings]

1 schematically shows an embodiment of a micropipette of the present invention, wherein (a) is an overall sectional view, (b) is a detailed view thereof, and (c) is a perspective view of a cavity portion.

FIG. 2 is an enlarged view of a portion A in FIG.

3 is a cross-sectional view taken along the line BB of FIG. 2, and is an explanatory view schematically showing a cross-sectional shape of a through-hole in a nozzle portion of the micropipette of the present invention in a direction perpendicular to an axial direction. Shows a case of a polygonal shape, and (b) shows a case of a crown shape.

FIG. 4 is a perspective view schematically showing a state of a protrusion of a through-hole in a nozzle portion in one embodiment (one example) of the micropipette of the present invention.

FIG. 5 is a cross-sectional view schematically showing a shape of a through-hole in a nozzle portion in another embodiment of the micropipette of the present invention, wherein (a) shows a case where a first point and a second point are different. (B) shows the case where the first point and the second point are matched.

FIG. 6 is a perspective view schematically showing a state of a protrusion of a through hole in a nozzle portion in another embodiment (another example) of the micropipette of the present invention.

FIG. 7 is an explanatory diagram schematically showing an example of a gradually decreasing cross-sectional area change of a through hole in a nozzle portion.

FIG. 8 schematically shows another embodiment of the micropipette of the present invention, wherein (a) is a plan view and (b) is G in (a).
It is -G sectional drawing.

FIG. 9 schematically shows another embodiment of the micropipette of the present invention, wherein (a) is a plan view and (b) is H in (a).
It is -H sectional drawing.

FIGS. 10A and 10B schematically show another embodiment of the micropipette of the present invention, wherein FIG. 10A is a plan view and FIG. 10B is a sectional view taken along line II of FIG.

FIG. 11 schematically shows another embodiment of the micropipette of the present invention, wherein (a) is a plan view, (b) is a side view,
(C) is an enlarged plan view of each composite, and (d) is a cross-sectional view of (c).

FIGS. 12A and 12B schematically show another embodiment of the micropipette of the present invention, wherein FIG. 12A is a plan view, and FIG. 12B is a JJ cross-sectional view of FIG.

13A and 13B schematically show another embodiment of the micropipette of the present invention, wherein FIG. 13A is a plan view, and FIG. 13B is a sectional view taken along line KK of FIG.

FIGS. 14A and 14B schematically show another embodiment of the micropipette of the present invention, wherein FIG. 14A is a plan view, and FIG. 14B is a sectional view taken along line LL of FIG.

FIG. 15 is a perspective view schematically showing one embodiment of the dispensing device of the present invention.

FIG. 16 schematically shows a micropipette used in the dispensing device of FIG. 15, (a) is a plan view, and (b) is a cross-sectional view taken along line MM of (a).

FIG. 17 is a perspective view schematically showing a situation in which a cartridge is attached to the dispensing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Pipette main body, 1a-1c ... Pipette member, 2 ... Sample injection port, 3 ... Cavity, 4 ... Nozzle part, 5 ... Through hole, 6 ... Sample discharge port, 7 ... Piezoelectric / electrostrictive element, 8 ... Projection ( Part), 10: micropipette, 11: nozzle plate, 12: pump part, 13: window, 14: spacer plate, 15: closing plate, 16: introduction hole, 17: communication hole, 18: upper electrode, 19 ... Piezoelectric / electrostrictive film, 20: lower electrode, 21: communication path, 22: introduction hole, 23: sample inlet end, 24: sample outlet end, 25: normal pipette, 26
... communication passage, 27 ... introduction hole, 28 ... communication passage, 29 ... fixing jig, 30 ... holding jig, 31 ... positioning pin, 32 ... fixing plate, 33 ... communication passage, 34 ... screw, 35 ... introduction hole, 36 ...
Communication passage, 37 adhesive, 38 surface on which sample inlet end is formed, 50a to 50c micropipette, 51a to 5
1c: sample outlet, 52a to 52c: sample inlet, 53
... Anisotropic flying-drop shielding plate, 55, dispensing device, 60, first cartridge.

Claims (22)

[Claims] 1. A sample injection port for injecting a sample from outside the pipette body into a pipette body, a cavity for introducing and temporarily storing the injected sample, and a stored sample passing through a through hole of a nozzle unit. And a sample ejection port for ejecting the sample to the outside, and a piezoelectric / electrostrictive element is provided on the outer surface of a portion corresponding to the cavity forming position of the pipette body, and the cavity is driven by driving the piezoelectric / electrostrictive element. A micropipette that changes the volume of the inside and discharges a certain amount of the sample stored in the cavity from the sample discharge port, and the cross-sectional shape of the through hole in the nozzle portion in the direction perpendicular to the axial direction is centered. A polygonal shape having an acute angle and an obtuse angle or a crown shape in which the projections and the projections are connected by a curve, and the cross section thereof Micropipette Jo area (sectional area) is, to the sample inlet end of the through hole to sample outlet end, characterized by being changed to continuously decreasing while maintaining substantially similar shape. 2. A sample inlet for injecting a sample from the outside of the pipette body into the pipette body, a cavity capable of introducing and temporarily storing the injected sample, and passing the stored sample through a through hole of a nozzle unit. And a sample ejection port for ejecting the sample to the outside, and a piezoelectric / electrostrictive element is provided on the outer surface of a portion corresponding to the cavity forming position of the pipette body, and the cavity is driven by driving the piezoelectric / electrostrictive element. A micropipette that changes the volume of the inside and discharges a certain amount of the sample stored in the cavity from the sample discharge port. The cross-sectional shape of the through hole in the nozzle in the direction perpendicular to the axial direction is The hole has a substantially circular shape from the sample inlet end to a first point spaced a predetermined distance from the sample outlet end, and the sample outlet end has three or more protrusions projecting radially from the center. In addition, the inner shape is a polygonal shape having an acute angle and an obtuse angle, or a crown shape in which projections are connected by a curve, and the area (cross-sectional area) of the cross-sectional shape is the first from the sample introduction port end of the through-hole. The micropipette is characterized in that the micropipette changes so as to continuously decrease gradually to the end of the sample outlet while maintaining a substantially circular shape up to the point. 3. The micropipette according to claim 1, wherein an angle between a straight line connecting an apex of the adjacent protrusion and the center of the polygonal shape or the crown shape having the protrusion is 1 to 120 degrees. . 4. The polygonal or crown-shaped side having the projections having a total length of 1.1 times or more the circumference of a circle having the same area as the polygon. The described micropipette. 5. A continuously decreasing rate of change of a cross-sectional area of a through-hole in the nozzle portion, wherein a rate of change of the cross-sectional area of the through-hole from a sample introduction port end to a sample discharge port end is a predetermined distance from a second point. The micropipette according to any one of claims 1 to 4, wherein the rate of change from the second point to the end of the sample outlet is larger than the rate of change. 6. The micropipette according to claim 1, wherein the surface roughness of the inner surface of the through hole in the nozzle portion is larger than that of the surface of the through hole where the sample inlet end is formed. 7. A liquid repellent treatment is applied to a surface of a through hole in the nozzle portion near an end of a sample discharge port.
7. The micropipette according to any one of 6. 8. The micropipette according to claim 1, wherein at least a portion of the pipette body corresponding to the cavity forming position and the piezoelectric / electrostrictive element setting position is made of zirconia ceramics. 9. The micropipette according to claim 8, wherein the zirconia ceramic is manufactured using a green sheet laminating and firing method. 10. The micropipette according to claim 1, wherein the portion of the pipette body where the sample discharge port is formed is made of resin. 11. The piezoelectric / electrostrictive element comprises a piezoelectric / electrostrictive film containing as a main component at least one lead compound selected from the group consisting of lead zirconate, lead titanate and lead magnesium niobate. A micropipette according to any one of claims 1 to 10. 12. The micrometer according to claim 1, wherein a plurality of said sample inlets, a plurality of said cavities, and a plurality of said sample outlets are formed in one pipette main body. pipette. 13. The pipette body comprises a plurality of first pipette members and one second pipette member, wherein the first pipette member has the cavity and the piezoelectric / electrostrictive element formed therein. A plurality of the sample inlets and a plurality of the sample outlets are formed in the second pipette member, and the plurality of the first pipette members and the one second pipette member are joined to each other; A micropipette according to any one of claims 1 to 11, comprising: 14. The micropipette according to claim 1, wherein the pipette body is formed of a flat plate, and a sample discharge port is formed on a side surface or a main plane of the pipette body. 15. The pipette body is formed of a flat plate, the sample outlet is formed on one main plane of the pipette body, and the sample inlet is formed on the other main plane. 14. The micropipette according to any one of 1 to 13. 16. The micropipette according to claim 1, wherein a plurality of the sample inlets are connected to one cavity. 17. A micropipette complex, wherein a plurality of micropipettes according to claim 1 are fixed to a fixing jig. 18. A dispensing device comprising a plurality of micropipettes according to any one of claims 1 to 16 or at least one micropipette complex according to claim 17, wherein said dispensing device is formed on said pipette body. A dispensing apparatus characterized in that the sample outlets are arranged vertically and horizontally, and different kinds of liquid samples are discharged from these sample outlets, respectively. 19. The dispensing device according to claim 18, wherein each of the sample injection ports is provided with a first cartridge separately filled with a different kind of liquid sample, and the different kind of sample can be discharged from the sample discharge port. apparatus. 20. Each of the sample injection ports is provided with a second cartridge filled with an aqueous solvent or an organic solvent, and a communication space from the sample injection port to the sample discharge port formed in the pipette body is cleaned. Claim 18 or 19 to obtain
A dispensing apparatus according to claim 1. 21. An anisotropic flying drop shielding plate made of a thin plate having an opening coaxial with the central axis of the sample discharge port is provided outside each of the sample discharge ports formed in the pipette main body. 21. The dispensing device according to any one of 20. 22. The use of the micropipette according to any one of claims 1 to 16, the micropipette complex according to claim 17, or the dispensing device according to any one of claims 18 to 21. Characteristic biochip manufacturing method.