JP3401526B2 - Apparatus and method for dispensing culture medium - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium dispensing device and method for dispensing a medium such as an agar medium used for various microorganism tests and the like into a petri dish or pour it with a sample.

[0002]

2. Description of the Related Art Generally, microbial tests related to GMP validation, such as sterility test in the pharmaceutical industry, bacteria limit test, environmental dropping bacteria test, antibiotic titer (potency) measurement, concentration measurement, etc. A medium such as an agar medium is widely used for a viable cell count test, a fungal count test, etc. in the food industry, and a microbial test related to HACC-based measures against contamination by harmful bacteria. The various microbial tests are roughly classified into a qualitative test and a quantitative test, but an agar medium is always used for the quantitative test.

By the way, in such various tests,
If the number of samplings is large and there are multiple types of medium, it takes a lot of time to sample the sample and dispense the medium. In addition, it was necessary to perform the above-mentioned medium dispensing operation in a sterile room or the like in order to improve the test accuracy. Therefore, an apparatus for automatically performing such sample sampling and medium dispensing work is disclosed in, for example, Japanese Patent Laid-Open Nos. 5-153961 and 4-1993.
It is disclosed in Japanese Patent Laid-Open No. 248980 and Japanese Patent Laid-Open No. 3-49676.

FIG. 9 is provided with a medium dispensing device 101 for dispensing a medium material and a mixing and agitating device 102 for diluting the medium material, and a sample diluent 103 is mixed with an agar medium 104 to automatically prepare a pour plate. It is a schematic block diagram of the dispensing / poursing apparatus 100 of the culture medium prepared in FIG. The dispensing / poursing apparatus 100 first takes out empty petri dishes 106 one by one from a rack 112 that stores them in a vertically stacked state, and carries them out onto a conveyor (not shown). Then, after the lid is opened, the petri dish 106 transported by the conveyor is dispensed with the diluted sample fluid dispensing device 109 with the diluted sample fluid 103. The diluted specimen liquid dispensing device 109 sequentially dilutes the specimen in the test tube with a diluting liquid in a plurality of dilution ratios, and dispenses the specimen diluting solution 103 to the petri dish 106 by the micro pipette 110.

Next, in the medium dispensing device 101, the molten agar medium 104 is passed from a medium reservoir (not shown) through a circulation pipe (not shown) and a branch pipe (not shown),
The set amount is supplied from the culture medium dispensing nozzle 105 into the dish 106. The mixing and stirring device 102 includes a stirring plate 10
7 is rotated by the rotation drive mechanism 108, so that the dish 106 is diluted by the diluted sample liquid dispensing device 109.
Sample dilution liquid 103 dispensed inside, and medium dispensing device 10
The molten agar medium 104 dispensed into the dish 106 by 1 is mixed and stirred.

Then, the diluted diluent sample liquid 10 is mixed.
3 and the agar medium 104 are solidified by the cooling device 111 to produce a pour plate. After that, the petri dish 106 with the lid attached is stored in the rack 113 in a vertically stacked state. Therefore, according to the medium dispensing / poursing apparatus 100 as described above, the pour plate can be automatically prepared by mixing the predetermined amount of the diluted sample liquid 103 and the agar medium 104. Of course, a plate medium can be prepared by omitting the step of dispensing the sample diluent 103 and dispensing only the agar medium 104.

[0007]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention By the way, in the dispensing and pour of a medium, the treatment differs depending on the type of test in which the medium is used. It is roughly divided into medium dispensing. Here, the pour step of mixing and stirring the diluted sample solution and the agar medium is performed only when the pour plate is prepared. Of these, for the dispensing / pouring of the plate medium and pour plate, the dispensing / pourning apparatus 100 as described above can be used. Since the amount is small and the dispensed medium is difficult to spread, automatic dispensing cannot be performed with the above-described dispensing / poursing apparatus 100.

That is, in the multi-layer dispensing, the amount of the medium for the seed layer to be stacked is small (for example, about 4 cc), and it is difficult for the medium to uniformly spread during dispensing, and the temperature of the previously solidified base layer is high. Has dropped to near room temperature (usually 20 to 24 ° C), so it must be spread quickly and evenly after dispensing. In addition, the thin layer dispensing is performed with a small amount of medium (for example, 5c).
c), and the surface of the petri dish is water-repellent due to the effect of the silicone-based mold release agent used for die-cutting of the plastic petri dish, which causes a problem that the medium is difficult to uniformly spread during dispensing. . Further, in the dispensing / poursing apparatus as described above, the dispensing / pouring of the plate medium and the pour plate is insufficient in fluidity depending on the concentration of the medium on the petri dish, and the smoothness of the medium is a problem. Was sometimes. or,
If the temperature of the medium is kept high, the fluidity of the medium can be maintained and a small amount can be dispensed. However, if the medium is heated to 50 ° C or higher, the bacteria of the sample will be killed. During the dispensing and pour work of the multi-layer medium or the thin layer medium, the temperature of the medium cannot be kept high to maintain the fluidity of the medium.

Therefore, in the conventional dispensing / poursing apparatus 100, for dispensing / pourning a plate medium and a pour plate, and for dispensing a multi-layer medium and a thin layer medium with a small amount (for example, less than 7 cc) of medium, Since it is not possible to dispense automatically, there is a problem in that it has to rely on human labor, which requires a great deal of labor and time.

Therefore, an object of the present invention is to solve the above-mentioned problems. Even if the amount of medium to be dispensed is small, the medium can be dispensed satisfactorily and uneven thickness of the medium can be ensured. It is possible to prevent the plate medium, pour plate,
An object of the present invention is to provide a medium dispensing device and method suitable for dispensing either a multi-layer medium or a thin layer medium.

[0011]

The above object of the present invention is to convey a petri dish along a predetermined path, and to a downstream side in the petri dish's conveying direction in the petri dish's conveyance path by the conveying means. A state in which the petri dish placed is tilted obliquely upward toward the downstream side in the transport direction by being inclined obliquely upward by a predetermined angle and performing a circular motion along a predetermined forward direction and a reverse direction in a horizontal plane. And a movable table that makes circular motions in the forward and reverse directions along the horizontal direction, and at least a portion of the movable table is in contact with the inner surface of the side wall of the petri dish downstream from the center in the transport direction. And a medium dispenser for dispensing a predetermined amount of medium to the medium dispenser.

Further, the above object of the present invention is to convey a petri dish along a predetermined path by a conveying means and to incline a predetermined angle obliquely upward toward the downstream side of the petri dish in the conveying direction. Place the dish on
In this state, a predetermined amount of medium is dispensed by the medium dispensing means so that at least a part of the medium comes into contact with the inner surface of the side wall of the dish on the downstream side in the transport direction from the center of the dish on the movable table, and further on the horizontal surface of the movable table. A circular motion along a predetermined forward direction and a backward direction is performed in the inside of the dish so that the placed petri dish is inclined obliquely upward toward the downstream side in the transport direction, and is circled in the forward direction and the backward direction along the horizontal direction. This is achieved by a method for dispensing a medium characterized by exercising.

Further, the above object of the present invention is to convey a petri dish along a predetermined path by a conveying means, place the petri dish on a movable table provided in the conveyance path, and in this state, move the table. In the upper dish, after discharging a predetermined amount of the medium from the medium dispensing nozzle of the medium dispensing means, by circularly moving the movable table along the predetermined forward and reverse directions in the horizontal plane, A method of dispensing a medium to be dispensed into a petri dish placed on a movable table, the relative position of the medium dispensing nozzle with respect to the movable table, the shape of the medium dispensing nozzle and the medium from the medium dispensing nozzle. By appropriately setting the discharge pressure of, the culture medium dispensed in the dish by the culture medium dispensing nozzle is dispensed so as to reach the entire inner surface of the side wall of the dish at substantially the same time. It is achieved by the dispensing method of that medium.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a schematic side view showing a movable table of a medium dispensing device according to a first embodiment of the present invention, and FIG. 2 is a medium dispensing means and a lid holding mechanism of the medium dispensing device shown in FIG. FIG. Further, FIG. 3 is a side view and a bottom view showing the tip shape of the medium dispensing nozzle of the medium dispensing means shown in FIG. 2, and FIGS.
FIG. 6 is a plan view showing an example of the state change of the medium dispensed in the petri dish by the medium dispensing means of the medium dispenser of FIG.

As shown in FIGS. 1 and 2, the medium dispenser of the present invention has a diameter of about 10 cm which is transferred to a movable table 30 by a petri dish transfer mechanism 20 which is a transfer means.
A medium such as an agar medium is dispensed into the dish 10 by the medium dispensing means 50. Then, the medium in the petri dish 10 is uniformly extended by a predetermined plane circular movement of the movable table 30. The petri dish transport mechanism 20 includes a transport path 21.
By pressing the petri dish 10 placed on the tray with the transport bar member 22, the petri dish 10 is transported in a predetermined direction (transport direction Z). The transport bar member 22 is fixed to an endless chain 23 wound around a sprocket (not shown) at a predetermined interval, and the endless chain 23 moves as the sprocket is driven by a driving means (not shown). To move along a predetermined path.

The movable table 30 is inclined obliquely upward at a predetermined angle θ (for example, θ = 4 °) toward the downstream side in the transport direction Z of the dish 10 in the transport path of the dish 10 by the dish transport mechanism 20. Further, it is provided with a support plate 31 that constitutes a part of the transport path 21. Furthermore,
The movable table 30 makes a circular motion along a predetermined positive direction and a reverse direction in a horizontal plane to thereby generate a support plate 31.
The petri dish 10 placed on the upper side is inclined obliquely upward at a predetermined angle θ toward the downstream side in the transport direction, and is forward and backward along the horizontal direction for a predetermined time (for example, forward and backward directions). Each can be circularly moved for 2 seconds.

That is, as shown in FIG. 1, the support plate 31 of the movable table 30 is fixed to the base plate 33 via the columns 32. Spring members 34, which are arranged substantially horizontally, are connected to substantially the center of the support columns 32, and the support members 32 are elastically restrained from moving horizontally in a predetermined range by the spring members 34. There is. A through hole 35 formed substantially in the center of a base plate 33 to which the support column 32 is fixed is provided to project from an upper surface of an eccentric rotary plate 38 fixed in a state of being eccentric with respect to a rotary shaft 40 of a motor 39 by a predetermined amount. The tip end of the shaft 36 is inserted through a bearing 37 so as to be relatively rotatable.

The base plate 33 is movably supported in a horizontal plane, and when the eccentric rotary plate 38 is eccentrically rotated by the rotation of the motor 39, the base plate 33 follows a predetermined forward direction and a reverse direction in the horizontal plane. You can make a circular motion. Therefore, with the circular motion of the base plate 33, the support plate 31 is circularly moved in the forward and reverse directions along the horizontal direction while being inclined obliquely upward toward the downstream side in the transport direction.

As shown in FIG. 2, the medium dispensing means 50 comprises
A predetermined amount of culture medium is discharged from the culture medium dispensing nozzle 51 in a predetermined direction at a predetermined pressure. That is, the medium dispensing nozzle 51
Is attached to the tip of the cylinder rod 53 of the air cylinder 52, and when the culture medium is dispensed,
In accordance with the above operation, a predetermined amount of the medium is discharged to the side of the petri dish 10 in a predetermined direction and a predetermined discharge pressure by a roller-type or shrunge-type medium dispensing pump (not shown).

In the medium dispensing means 50, a medium pool is formed in the petri dish 10 on the movable table 30 downstream from the center in the transport direction Z, and at least a part of the medium pool is in the dish 10. The medium is dispensed into the petri dish 10 so as to contact the inner surface of the side wall. In addition,
As shown in FIG. 3A, the tip of the culture medium dispensing nozzle 51 has a shape that widens downward in a side view. Further, as shown in FIG. 3B, the flow path opening 54 of the culture medium dispensing nozzle 51 is formed in an oval shape whose longitudinal direction is along the flow direction of the culture medium. For example, the dimension A = 2 mm and the dimension B. = 2.5
set to mm.

A lid holding mechanism 60 is provided above the movable table 30 as shown in FIG. The lid holding mechanism 60 sucks the lid 11 of the dish 10 on the movable table 30 by the suction plate 62 provided at the tip of the holding arm 61 before the medium is dispensed to the dish 10 by the medium dispensing means 50. The lid 11 is lifted and lifted as the holding arm 61 rises, and the lid 11 is opened. Further, the lid holding mechanism 60, after the medium is dispensed into the dish 10, before the circular movement by the movable table 30,
By lowering the holding arm 61 and releasing the suction of the lid 11 by the suction disk 62, the lid 11 is put on the petri dish 10.

Next, the operation of the first embodiment will be described with reference to FIGS. 1 and 4 to 6. For example, when a thin-layer flat plate is dispensed by the dispensing device according to the first embodiment, the dish 10 supplied from a dish supply unit (not shown) is transported to the movable table 30 by the dish transport mechanism 20. Then, it is placed on the support plate 31.

Petri dish 10 on the movable table 30
After the lid 11 is removed by the lid holding mechanism 60,
A predetermined amount (about 5 cc) of the medium containing viable bacteria is dispensed from the medium dispensing nozzle 51 of the medium dispensing means 50. At this time, as shown in FIG. 4 (a), FIG. 5 (a), or FIG. 6 (a), the medium dispensing means 50 forms a medium reservoir on the downstream side in the transport direction Z from the center in the petri dish 10. Further, the medium is dispensed into the dish 10 so that at least a part of the medium pool contacts the inner surface of the side wall of the dish 10. However, in FIG. 4 (a), the upper part of the medium puddle contacts the inner surface of the side wall of the petri dish 10, and in FIG. 5 (a) the lower part of the medium puddle contacts the inner wall surface of the petri dish 10, In FIG. 6A, the upper part and the lower part of the medium pool contact with the inner surface of the side wall of the petri dish 10. For the dispensed medium, the support plate 31 moves in the transport direction Z.
As shown in FIG. 4 (b), FIG. 5 (b) or FIG. 6 (b), the slanting direction is inclined obliquely upward toward the downstream side, so that the upstream side in the transport direction Z in the petri dish 10 as shown in FIG. Flow to.

Further, the petri dish 10 into which the medium has been dispensed is covered with the lid 11 again by the lid holding mechanism 60.
In this state, the movable table 30 is normally rotated for a predetermined time (for example, 2 seconds), and the placed petri dish 10 is tilted obliquely upward toward the downstream side in the transport direction by an angle θ, and is moved in the forward direction along the horizontal direction. It is a circular motion. As a result, the medium is
As shown in (c), FIG. 5 (c) or FIG. 6 (c), it flows so as to cover the downstream side in the transport direction Z from the center in the petri dish 10.

Next, the movable table 30 is reversely rotated for a predetermined time (for example, 2 seconds), and the placed petri dish 10 is tilted obliquely upward toward the downstream side in the transport direction by an angle θ, which is the reverse direction along the horizontal direction. It is circularly moved. As a result, the culture medium flows so as to cover the upstream side in the transport direction Z from the center in the petri dish 10 and uniformly extends, as shown in FIG. 4 (d), FIG. 5 (d), or FIG. 6 (d).

Then, after the culture medium in the dish 10 is uniformly spread by the circular motion of the movable table 30 as described above, the dish 10 is immediately conveyed to the next horizontal stage, which is horizontally secured, and is then leveled. A certain period of time (for example, 8
It is left to stand for a second. As a result, the medium in the petri dish 10 is uniformly solidified without unevenness in thickness.
After that, the petri dish 10 has a label sticking portion (not shown).
The label is attached to a label (not shown) in which the necessary information such as the type of bacteria, the sample number, and the date of dispensing is bar-coded and displayed at the label attaching section. The petri dish 10 to which the label is attached is a petri dish stack storage unit (not shown).
It is transported to and stored in. Incidentally, in the above embodiment, the case of dispensing a thin layer plate was described, but it goes without saying that it can be suitably used for any of plate medium, pour plate, multi-layer medium or thin layer medium. .

That is, according to the medium dispensing / pouraging method of the present invention, at least one predetermined amount of medium is provided by the medium dispensing means 50 downstream from the center in the petri dish 10 on the movable table 30 in the transport direction. The petri dish 10 is dispensed so that it contacts the inner surface of the side wall of the petri dish 10, and the petri dish 10 placed on the movable table 30 is tilted obliquely upward toward the downstream side in the transport direction, and in the forward direction along the horizontal direction. And circular movement in the opposite direction causes flows in different directions in the medium, the flow in one direction collides with the flow in the other direction, and the medium is uniformly dispensed. In addition, a pour plate having a pour step can be easily prepared, and uneven thickness of the medium can be reliably prevented.

In the first embodiment described above, the support plate 31 is inclined 4 degrees obliquely upward toward the downstream side in the transport direction Z, but the present invention is not limited to this, and this inclination angle is not limited to this. Is appropriately selected according to the type of agar medium and the amount dispensed. Further, the present invention is not limited to the configurations of the petri dish transport mechanism 20, the movable table 30, and the medium dispensing means 50 in the first embodiment, and various configurations can be adopted.

FIG. 7 is a side view and a bottom view showing the tip shape of the medium dispensing nozzle of the medium dispensing means of the medium dispensing device according to the second embodiment of the present invention. Further, FIG. 8 is a plan view showing a state change of the medium dispensed in the medium dispensing nozzle and the petri dish of the medium dispensing means shown in FIG. 7. In the second embodiment, the relative position of the medium dispensing nozzle 70 with respect to a horizontally movable table (not shown), the shape of the medium dispensing nozzle 70, and the discharge pressure of the medium from the medium dispensing nozzle 70 are The medium that is appropriately set and dispensed into the dish 10 by the medium dispensing nozzle 70 is
Are set so that they reach the entire inner surface of the side wall at about the same time. In addition, in FIG. 8, the arrow indicates the extending direction of the medium.

For example, in the case of multi-layer dispensing, after dispensing and solidifying the base layer medium, a predetermined amount (for example, 4 cc) of the seed layer medium is dispensed and diffused. In addition, the temperature of the previously solidified base layer medium is room temperature (22 to 25 ° C).
Since the solidification temperature of the agar medium is usually around 37 ° C, the medium of the seed layer tends to solidify as soon as it is dispensed. Therefore, the shape of the culture medium flow passage 71 of the culture medium dispensing nozzle 70 is formed in a required shape in which the flow passage diameter becomes smaller from the predetermined location 72 (for example, the flow passage diameter C on the tip side is C =
4 mm, the flow path diameter on the base end side D = 6 mm), and the medium of the seed layer dispensed with the momentum of dispensing is moved in the radial direction of the dish 10. Therefore, the seed layer medium that moves on the hydrophilic base layer medium reaches the entire inner surface of the side wall of the petri dish 10 substantially at the same time.

Immediately after the dispensing is completed, the lid is closed, and the movable table is circularly moved in the forward and reverse directions along the horizontal direction for a predetermined time (for example, forward rotation for 2 seconds and reverse rotation for 2 seconds), whereby the medium of the base layer is cultivated. Assists the growth of the seed layer medium above,
The seed layer medium can extend uniformly. That is, in this embodiment, in the multi-layer dispensing, the medium is dispensed by the medium dispensing nozzle 70 having the above-described shape in a radial direction of the dish 10 on the medium of the hydrophilic base layer. The medium of the seed layer is uniformly extended by moving the movable table so as to reach the entire inner surface of the side wall of the petri dish 10 substantially at the same time and by circularly moving the movable table. Therefore, even if the dispensed amount of the seed layer medium to be laminated is small (for example, about 4 cc), the seed layer medium can be uniformly spread, and uneven thickness of the medium can be reliably prevented. it can.

The present invention is not limited to the shape of the medium dispensing nozzle 70 in the second embodiment, and the medium dispensed in the petri dish by the medium dispensing nozzle is
It goes without saying that various shapes can be adopted as long as they can be dispensed so as to reach the entire inner surface of the side wall of the petri dish at substantially the same time.

[0033]

As described above, according to the medium dispensing apparatus and method of the present invention, even if the amount of medium dispensed is small, the medium is uniformly dispensed or the sample is mixed with the sample. It is possible to reliably prevent unevenness in the thickness of the medium. Therefore, it is possible to automate any dispensing work of a plate medium, a pour plate, a multi-layer medium or a thin layer medium, and improve the workability of such a dispensing work and the inspection accuracy and reliability. I was able to.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a movable table of a medium dispensing device according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a medium dispensing means and a lid holding mechanism of the medium dispensing device shown in FIG.

3A and 3B are a side view and a bottom view showing a tip shape of a culture medium dispensing nozzle of the culture medium dispensing means shown in FIG.

FIG. 4 is a plan view showing an example of the state change of the medium dispensed in the petri dish by the medium dispensing means of the medium dispenser of FIG.

5 is a plan view showing another example of the state change of the medium dispensed in the petri dish by the medium dispensing means of the medium dispenser of FIG. 1. FIG.

6 is a plan view showing still another example of the state change of the medium dispensed in the petri dish by the medium dispensing means of the medium dispenser of FIG. 1. FIG.

FIG. 7 is a side view and a bottom view showing a tip shape of a medium dispensing nozzle of a medium dispensing unit of a medium dispensing device according to a second embodiment of the present invention.

8 is a plan view showing a state change of the medium dispensed in the medium dispensing nozzle and the dish of the medium dispensing means shown in FIG. 7.

FIG. 9 is a schematic configuration diagram of a conventional medium dispensing device.

[Explanation of symbols] 10 Petri dish 20 Petri dish transport mechanism (transport means) 21 Transport path 22 Transport bar member 30 movable table 31 Support plate 32 props 33 base plate 38 Eccentric rotating plate 39 motor 50 Medium Dispensing Means 51 Medium dispensing nozzle

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C12M 1/00-1/34

Claims (3)

(57) [Claims] 1. A transporting means for transporting a petri dish along a predetermined path, and a slanting path slanting upward at a predetermined angle toward the downstream side of the petri dish in the transporting path of the petri dish by the transporting means. , By performing a circular motion along a predetermined forward direction and a reverse direction in a horizontal plane, the placed petri dish is tilted obliquely upward toward the downstream side in the transport direction, and the forward direction and the reverse direction along the horizontal direction. A movable table to be circularly moved to, and a downstream side in the transport direction from the center in the petri dish placed on the movable table, a medium portion for dispensing a predetermined amount of the medium so that at least a part comes into contact with the inner surface of the side wall of the petri dish. An aliquoting device for a medium, which comprises an injection means. 2. The petri dish is transported by a transporting means along a predetermined path, and the petri dish is placed on a movable table provided obliquely upward and inclined at a predetermined angle toward the downstream side in the transport direction of the petri dish. In this state, a predetermined amount of the medium is dispensed by the medium dispensing means so that at least a part of the medium comes into contact with the inner surface of the side wall of the dish on the downstream side in the transport direction from the center of the dish on the movable table, and then the movable table By making a circular motion along a predetermined forward direction and a reverse direction in a horizontal plane, the placed petri dish is tilted obliquely upward toward the downstream side in the transport direction, and then in the forward and reverse directions along the horizontal direction. A method for dispensing a medium, which comprises circularly moving the medium. 3. The petri dish is conveyed along a predetermined path by a conveying means, the petri dish is placed on a movable table provided in the conveying path, and in this state, the medium is placed in the petri dish on the movable table. The medium was placed on the movable table by discharging a predetermined amount of the medium from the medium dispensing nozzle of the dispensing means and then circularly moving the movable table along a predetermined forward direction and a reverse direction in a horizontal plane. A method of dispensing a medium to be dispensed into a petri dish, the relative position of the medium dispensing nozzle with respect to the movable table,
By appropriately setting the shape of the culture medium dispensing nozzle and the discharge pressure of the culture medium from the culture medium dispensing nozzle, the culture medium dispensed by the culture medium dispensing nozzle into the petri dish is substantially distributed over the entire inner surface of the side wall of the petri dish. A method for dispensing a culture medium, which dispenses so as to arrive at the same time.