JPH119261A - Device for dividing and injecting culture medium and dividing and injecting of the same medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suitable dividing and injecting apparatus capable of satisfactorily carrying out injection of culture medium even if dividing and injecting amount of the culture medium is small and a method for dividing and injecting. SOLUTION: This dividing and injecting apparatus for culture medium is equipped with a Petri dish 10-carrying mechanism 20 for carrying Petri dish 10 along a prescribed pathway, a movable table 30 provided in a state inclined by a prescribed angle θ obliquely upwardly toward the downstream side in carrying direction of Petri dish 10 on carrying way of Petri dish by the Petri dish-carrying mechanism 20 and subjecting placed Petri dish 10 to circular movement in normal direction and reverse direction in horizontal direction in a state inclined obliquely upwardly toward the downstream side in the carrying direction by carrying out circular movement in prescribed normal direction and reverse direction in horizontal surface and a culture medium-dividing and injecting means for dividing and injecting. a prescribed amount of culture medium so as to bring at least part thereof into contact with side wall inner face of Petri dish 10 on downstream side in carrying direction than the center in the Petri dish 10 placed on the movable table 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for dispensing a medium, such as an agar medium, used for various kinds of microbial tests into a petri dish or mixing with a specimen.

[0002]

2. Description of the Related Art In general, microbial tests related to GMP validation, such as sterility test, bacterial count limit test, environmental drop bacteria test, antibiotic titer (efficacy) measurement, and concentration measurement in the pharmaceutical industry, for example, Mediums such as agar medium are widely used for microbial tests related to measures to prevent contamination by harmful bacteria based on HACCP, such as viable cell count tests and fungal count tests in the food industry. Such various microbial tests are roughly classified into a qualitative test and a quantitative test, and an agar medium is always used for the quantitative test.

By the way, in such various tests,
When the number of samplings is large and there are a plurality of types of culture media, a great deal of time is required for sample sampling and dispensing of culture media. Further, it is necessary to perform the above-described dispensing operation of the culture medium in an aseptic room or the like in order to increase the test accuracy. Therefore, an apparatus for automatically performing such sampling of a sample and dispensing of a culture medium is disclosed in, for example, Japanese Patent Application Laid-Open Nos.
248980 and JP-A-3-49676.

FIG. 9 shows a medium dispensing device 101 for dispensing a medium material and a mixing / stirring device 102 for diluting the medium material. A sample diluent 103 is mixed with an agar medium 104 to automatically form a pour plate. FIG. 1 is a schematic configuration diagram of a dispensing / pouring device 100 for a medium prepared in FIG. The dispensing / pouring apparatus 100 first takes out empty petri dishes 106 one by one from a rack 112 that is stored in a vertically stacked state and carries them out onto a conveyor (not shown). After the lid is opened on the petri dish 106 conveyed by the conveyor, the sample diluent 103 is dispensed by the diluting sample liquid dispenser 109. The diluted sample liquid dispensing device 109 sequentially dilutes the sample in the test tube at a plurality of dilution ratios with a diluting liquid, and dispenses the sample diluent 103 into a petri dish 106 using a micropipette 110.

Next, in the medium dispensing apparatus 101, the molten agar medium 104 is transferred from a medium storage tank (not shown) through a circulation pipe (not shown) and a branch pipe (not shown).
A set amount is supplied from the culture medium dispensing nozzle 105 into the petri dish 106. The mixing and stirring device 102 includes a stirring plate 10
7 is rotated by the rotation drive mechanism 108, and the petri dish 106 is
The sample diluent 103 dispensed into the inside and the medium dispensing device 10
1 is mixed and stirred with the molten agar medium 104 dispensed into the petri dish 106.

[0006] The mixed diluent sample liquid 10
3 and the agar medium 104 are solidified by the cooling device 111 to produce a pour plate. Thereafter, the petri dish 106 with the lid attached is stored in a rack 113 in a vertically stacked state. Therefore, according to the medium dispensing / pouring apparatus 100 as described above, a pour plate can be automatically prepared by mixing a predetermined amount of the diluent sample liquid 103 and the agar medium 104. Of course, if the step of dispensing the sample diluent 103 is omitted and only the agar medium 104 is dispensed, a plate medium can be prepared.

[0007]

The dispensing / pouring of a medium depends on the type of the test in which the medium is used, and is divided into four types: a plate medium, a pour plate, a layered medium, and a thin layer medium. It is roughly divided into medium dispensing. Here, the pour step of mixing and agitating the diluted sample liquid and the agar medium is performed only when preparing a pour plate. Among these, the dispensing / pouring apparatus 100 as described above can be used for dispensing / pouring of the plate medium and the pour plate, but the dispensing of the overlay medium and the thin layer medium is performed by dispensing the medium. In addition to the small volume, the dispensed medium may not be easily extended, so that the dispensing / pouring device 100 as described above could not automatically dispense.

[0008] That is, in the multi-layer dispensing, the dispensing amount of the medium of the seed layer to be laminated is small (for example, about 4 cc), the medium is difficult to uniformly spread at the time of dispensing, and the temperature of the previously solidified base layer Has dropped to near room temperature (usually 20 to 24 ° C.), so that it must be spread quickly and uniformly after dispensing. Further, in the thin layer dispensing, the dispensing amount of the medium is small (for example, 5c).
c), and since the surface of the petri dish has water repellency due to the effect of the silicone release agent used for removing the plastic petri dish, there is a problem that the medium is difficult to uniformly spread during dispensing. . Further, in the dispensing / pouring device 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 problematic. Was sometimes or,
If the temperature of the medium is maintained at a high temperature, 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 more, the bacteria of the specimen will be killed. During the dispensing / pouring operation of the layered medium or the thin layered medium, the medium cannot be maintained at a high temperature to maintain the fluidity of the medium.

Therefore, in the conventional dispensing / pouring apparatus 100, the dispensing / pouring of a plate medium and a pour plate, and the dispensing of a layered medium and a thin layer medium with a small amount (for example, less than 7 cc) of a medium are not described. Since automatic dispensing cannot be performed, there has been a problem that a large amount of labor and time are required due to having to rely on manual labor.

[0010] Accordingly, an object of the present invention is to solve the above-mentioned problems, and it is possible to satisfactorily dispense a medium even if the amount of the medium is small, and to surely prevent unevenness in the thickness of the medium. Plate medium, pour plate,
It is an object of the present invention to provide a medium dispensing apparatus and method suitable for dispensing any of a multilayer medium and a thin layer medium.

[0011]

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

[0012] It is another object of the present invention to provide a movable table, which is provided with a petri dish which is conveyed along a predetermined path by a conveying means, and which is provided obliquely upward at a predetermined angle toward a downstream side in the conveying direction of the petri dish. Place the dish on
In this state, a predetermined amount of culture medium is dispensed by the culture medium dispensing means such that at least a part thereof comes into contact with the inner surface of the side wall of the petri dish on the downstream side in the transport direction from the center in the petri dish on the movable table. The circular motion in the forward and reverse directions along the horizontal direction in a state in which the placed petri dish is inclined obliquely upward toward the downstream side in the transport direction by making a circular motion along the predetermined forward and reverse directions. This is achieved by a method of dispensing a medium characterized by exercising.

Further, the object of the present invention is to transport a petri dish along a predetermined path by a transport means, and place the petri dish on a movable table provided in the transport path. After discharging a predetermined amount of the culture medium from the culture medium dispensing nozzle of the culture medium dispensing means into the upper petri dish, the movable table is circularly moved along the predetermined forward and reverse directions in the horizontal plane, thereby forming the culture medium. A method for dispensing a medium to be dispensed into a petri dish placed on a movable table, comprising: a relative position of a medium dispensing nozzle with respect to the movable table, a shape of the medium dispensing nozzle, and a medium from the medium dispensing nozzle. By appropriately setting the discharge pressure of the medium, the medium dispensed into the Petri dish by the medium dispensing nozzle is dispensed such that the medium reaches the entire inner surface of the side wall of the Petri dish substantially simultaneously. It is achieved by the dispensing method of that medium.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic side view showing a movable table of a medium dispensing apparatus 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 apparatus shown in FIG. FIG. FIG. 3 is a side view and a bottom view showing the tip shape of the culture medium dispensing nozzle of the culture medium dispensing means shown in FIG. 2, and FIGS.
FIG. 4 is a plan view showing an example of a state change of a medium dispensed into a petri dish by a medium dispensing means of the medium dispensing device of FIG.

As shown in FIGS. 1 and 2, the culture medium dispensing apparatus of the present invention has a diameter of about 10 cm which is transported to a movable table 30 by a petri dish transport mechanism 20 which is a transport means.
A medium such as an agar medium is dispensed into the Petri dish 10 by the medium dispensing means 50. Then, the medium in the Petri dish 10 is uniformly extended by a predetermined plane circular motion 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 at predetermined intervals to an endless chain 23 wound around a sprocket (not shown), and the endless chain 23 moves with the rotation of the sprocket driven by a driving unit (not shown). Moves along a predetermined route.

The movable table 30 is inclined obliquely upward at a predetermined angle θ (eg, θ = 4 °) toward the downstream side in the transport direction Z of the petri dish 10 in the transport path of the petri dish 10 by the petri dish transport mechanism 20. Further, a support plate 31 constituting a part of the transport path 21 is provided. Furthermore,
The movable table 30 makes a circular motion along predetermined forward and reverse directions in a horizontal plane, thereby supporting the 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 for a predetermined time in the forward and reverse directions along the horizontal direction, respectively (for example, in the forward and reverse directions). For 2 seconds each).

That is, as shown in FIG. 1, the support plate 31 of the movable table 30 is fixed to a base plate 33 via a support post 32. A substantially horizontal spring member 34 is connected to substantially the center of the column 32, and each column 32 is elastically restricted in a predetermined range by a spring member 34 in a horizontal direction. I have. A through-hole 35 formed substantially at the center of the base plate 33 to which the column 32 is fixed is protruded from an upper surface of an eccentric rotary plate 38 fixed eccentrically to a rotary shaft 40 of a motor 39 by a predetermined amount. The distal end of the shaft 36 is inserted via a bearing 37 so as to be relatively rotatable.

The base plate 33 is movably supported in a horizontal plane. When the eccentric rotary plate 38 is eccentrically rotated with the rotation of the motor 39, the base plate 33 moves along predetermined forward and reverse directions in the horizontal plane. You can make a circular motion. Accordingly, 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 end of the cylinder rod 53 of the air cylinder 52, and when dispensing the culture medium, the air cylinder 52
Along with the operation, the medium is projected toward the petri dish 10 in a predetermined direction, and a predetermined amount of medium is discharged at a predetermined discharge pressure by a roller type or a syringe type medium dispensing pump (not shown).

The medium dispensing means 50 forms a pool of culture medium downstream of the center of the petri dish 10 on the movable table 30 in the transport direction Z, and at least a part of the pool of culture medium is 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 downwardly divergent shape in a side view. 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. = 2.5
mm.

A lid holding mechanism 60 is provided above the movable table 30, as shown in FIG. Before the culture medium is dispensed into the petri dish 10 by the culture medium dispensing means 50, the lid holding mechanism 60 suctions the lid 11 of the petri dish 10 on the movable table 30 by the suction disk 62 provided at the tip of the holding arm 61. The lid 11 is lifted as the holding arm 61 is raised, and the lid 11 is opened. Further, after the medium is dispensed into the petri dish 10 and 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 board 62, the lid 11 is put on the petri dish 10.

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

Petri dish 10 on movable table 30
After the lid 11 is removed by the lid holding mechanism 60,
A predetermined amount (approximately 5 cc) of the culture medium containing live bacteria is dispensed from the culture medium dispensing nozzle 51 of the culture 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 pool of the medium on the downstream side in the transport direction Z from the center in the petri dish 10. The medium is dispensed into the Petri dish 10 so that at least a part of the medium pool contacts the inner surface of the side wall of the Petri dish 10. However, in FIG. 4 (a), the upper part of the culture medium in the figure contacts the inner surface of the side wall of the petri dish 10, and in FIG. 5 (a), the lower part of the culture medium in the figure contacts the inner surface of the side wall of the petri dish 10, In FIG. 6A, the upper and lower portions of the medium pool in the drawing are in contact with the inner surface of the side wall of the petri dish 10. In the dispensed medium, the support plate 31 is moved in the transport direction Z.
As shown in FIG. 4 (b), FIG. 5 (b) or FIG. 6 (b), by being inclined obliquely upward at a predetermined angle θ toward the downstream side, the upstream side in the transport direction Z in the petri dish 10 Flows to

Further, the petri dish 10 into which the medium has been dispensed is again covered with the lid 11 by the lid holding mechanism 60.
In this state, the movable table 30 is rotated forward for a predetermined period of time (for example, 2 seconds), and the placed petri dish 10 is tilted obliquely upward at an angle θ toward the downstream side in the transport direction. Circular motion. Thus, the culture medium is as shown in FIG.
(C), as shown in 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 rotated in the reverse direction for a predetermined time (for example, 2 seconds), and the mounted petri dish 10 is tilted obliquely upward at an angle θ toward the downstream side in the transport direction. It is moved circularly. Thereby, as shown in FIG. 4 (d), FIG. 5 (d) or FIG. 6 (d), 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 extends uniformly.

After the medium in the petri dish 10 is uniformly spread by the above-described circular movement of the movable table 30, the petri dish 10 is immediately conveyed to the next horizontal stage where the horizontal is secured, and For a predetermined time (for example, 8
(Seconds). Thereby, the culture medium in the Petri dish 10 is uniformly solidified without causing unevenness in thickness or the like.
Thereafter, the petri dish 10 is attached to a label attaching section (not shown).
In a label attaching section, a label (not shown) in which necessary information such as a type of bacteria, a sample number, and a dispensing date is bar-coded and displayed is attached. The petri dish 10 with the label attached thereto is a petri dish storage unit (not shown).
Transported and stored. In the above embodiment, the case of dispensing a thin layer plate has been described, but it goes without saying that it can be suitably used for dispensing any of a plate medium, a pour plate, an overlay medium, and a thin layer medium. .

That is, according to the method for dispensing and pruning the medium of the present invention, at least one predetermined amount of the medium is dispensed by the medium dispensing means 50 downstream from the center of the petri dish 10 on the movable table 30 in the transport direction. The petri dish is dispensed so that the portion comes into contact with 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 in the forward direction along the horizontal direction. By performing a circular motion in the opposite direction, a flow in a different direction is generated in the medium, and a flow in one direction collides with a flow in the other direction, and the medium is dispensed uniformly. In addition, a pour plate having a pour step can be easily prepared, and the thickness unevenness of the medium can be reliably prevented.

In the first embodiment, the support plate 31 is inclined obliquely upward by 4 degrees toward the downstream side in the transport direction Z. However, the present invention is not limited to this, and the inclination angle Is appropriately selected according to the type of the agar medium, the dispensed amount, and the like. 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 described above, and may adopt various configurations.

FIG. 7 is a side view and a bottom view showing the tip shape of a medium dispensing nozzle of a medium dispensing means of a medium dispensing apparatus according to a second embodiment of the present invention. FIG. 8 is a plan view showing a state change of the medium dispensed to the medium dispensing nozzle and the Petri dish of the medium dispensing means shown in FIG. In the second embodiment, the relative position of the culture medium dispensing nozzle 70 with respect to a horizontally movable table (not shown), the shape of the culture medium dispensing nozzle 70, and the discharge pressure of the culture medium from the culture medium dispensing nozzle 70 are reduced. The culture medium, which is appropriately set and dispensed into the petri dish 10 by the culture medium dispensing nozzle 70,
Are set so as to reach almost the entire inner surface of the side wall at the same time. Note that, in FIG. 8, arrows indicate the direction in which the culture medium extends.

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

As soon as 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 period of time (for example, normal rotation 2 seconds, reverse rotation 2 seconds), and thereby the medium in the base layer is formed. Helping the seed layer grow above
The seed layer medium can extend uniformly. That is, in the present embodiment, at the time of multi-layer dispensing, the medium is dispensed with the medium dispensing nozzle 70 having the above-described shape, and the medium is dispensed in the radial direction of the Petri dish 10 on the medium of the hydrophilic base layer. By moving the movable table so as to reach the entire inner surface of the side wall of the petri dish almost simultaneously, and by moving the movable table in a circular motion, the medium of the seed layer is uniformly extended. Therefore, even if the dispensed amount of the medium of the seed layer to be laminated is small (for example, about 4 cc), the medium of the seed layer can be uniformly spread, and the thickness unevenness 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 into the petri dish by the medium dispensing nozzle is
It goes without saying that various shapes can be adopted as long as the shape can be dispensed so as to reach almost the entire inner surface of the side wall of the petri dish at the same time.

[0033]

As described above, according to the medium dispensing apparatus and method of the present invention, even if the medium is dispensed in a small amount, the medium is dispensed or evenly mixed with the sample. Thus, the thickness unevenness of the medium can be reliably prevented. Therefore, it is possible to automate the dispensing operation of any of the plate medium, the pour plate, the layered medium and the thin layer medium, and to improve the workability of such dispensing work and the inspection accuracy and reliability. Was completed.

[Brief description of the drawings]

FIG. 1 is a schematic side view showing a movable table of a culture medium dispensing apparatus 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 apparatus shown in FIG.

3 is a side view and a bottom view showing a tip shape of a medium dispensing nozzle of the medium dispensing means shown in FIG.

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

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

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

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

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Petri dish 20 Petri dish conveying mechanism (conveying means) 21 Conveying path 22 Conveying bar member 30 Movable table 31 Support plate 32 Prop 33 Base plate 38 Eccentric rotating plate 39 Motor 50 Medium dispensing means 51 Medium dispensing nozzle

 ────────────────────────────────────────────────── ─── Continued on front page (72) Inventor Masato Ichikawa 2-58 Hiromachi, Shinagawa-ku, Tokyo Sankyo Co., Ltd.

Claims (3)

[Claims] 1. A transport means for transporting a petri dish along a predetermined path, and provided in a transport path of the petri dish by the transport means at a predetermined angle inclined obliquely upward toward a downstream side in a transport direction of the petri dish. In a horizontal plane, by performing circular motion along predetermined forward and reverse directions, the placed petri dish is inclined obliquely upward toward the downstream side in the transport direction and forward and backward along the horizontal direction. A movable table that makes a circular motion; and a medium portion for dispensing a predetermined amount of medium so that at least a part thereof is in contact with the inner surface of the side wall of the Petri dish downstream from the center in the Petri dish placed on the movable table. A dispensing device for a culture medium, comprising a dispensing means. 2. A petri dish is conveyed along a predetermined path by a conveying means, and the petri dish is placed on a movable table which is provided obliquely upward at a predetermined angle toward a downstream side in the conveying direction of the petri dish. In this state, a predetermined amount of medium is dispensed by the medium dispensing means so that at least a part thereof contacts the inner surface of the side wall of the petri dish on the downstream side in the transport direction from the center in the petri dish on the movable table. By making a circular motion along the predetermined forward and reverse directions in the horizontal plane, the placed petri dish is inclined obliquely upward toward the downstream side in the transport direction in the forward and reverse directions along the horizontal direction. A method for dispensing a culture medium, characterized by circular movement. 3. A petri dish is transported along a predetermined path by a transport means, and the petri dish is placed on a movable table provided in the transport path, and in this state, a culture medium is placed in the petri dish on the movable table. After discharging a predetermined amount of culture medium from the culture medium dispensing nozzle of the dispensing means, the movable table was circularly moved along a predetermined forward and reverse direction in a horizontal plane, whereby the culture medium was placed on the movable table. A method for dispensing a medium to be dispensed into a petri dish, wherein a relative position of a 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 into the Petri dish by the culture medium dispensing nozzle is substantially entirely on the inner surface of the side wall of the Petri dish. A method for dispensing a medium, which comprises dispensing so as to reach at the same time.