JP6268992B2 - Medium solution coating method and porous nozzle - Google Patents

Description

  The present invention relates to a technique for applying a medium solution for forming a dry medium used for viable count inspection.

  In the food manufacturing industry, in order to control the quality and hygiene of products, viable count tests using agar media are performed. FIG. 6 is a diagram for explaining the viable cell count test using an agar medium. As shown in FIG. 6, the viable cell count test using an agar medium is a gelled agar medium formed in a Petri dish 9a1 (glass petri dish), and after dropping a sample solution with a dropper 9a2, etc. This is a test to measure the number of viable bacteria after a certain time. The viable cell count test using an agar medium has been widely used for a long time, but it requires an agar medium with agar in the Petri dish 9a1, so it takes time to adjust the medium and is not suitable for testing many samples. there were.

  In recent years, in order to increase the efficiency of viable count testing, an increasing number of companies have introduced viable count testing using a dry medium instead of an agar medium. The dry medium means that the medium components are not gelled (dried) and applied in advance to a resin sheet or container, and the gelation proceeds at the stage where the sample solution is dropped during the viable count test. It is a culture medium which can obtain the same effect. In the viable cell count test using a dry culture medium, there is no need to adjust the culture medium at the site where the viable cell count test is performed, so that the efficiency of the viable cell count test can be greatly improved.

  Petrifilm (registered trademark) manufactured by 3M is well-known as a product already marketed in such a dry medium. FIG. 7 is a diagram for explaining the Petri film (registered trademark) 9b. As shown in FIG. 7, the Petri film (registered trademark) 9b is composed of a waterproof flat plate 9b1 (plastic coated paper) and a cover film 9b2 that overlaps the waterproof flat plate 9b1. A dry medium is formed by applying about and then applying a cold water soluble gel (gelling agent) and medium components on it, which is further sterilized into a product. Such a sheet-like dry medium is also called a film medium.

  FIG. 8 is a diagram for explaining how to use Petri Film (registered trademark) 9b. When using Petrifilm (registered trademark) 9b, first, the cover film 9b2 overlaid on the flat plate 9b1 is lifted (FIG. 8 (a)), and the medium components and cold water soluble gel formed on the flat plate through the adhesive layer A predetermined amount of a sample solution is dropped on a dry medium consisting of (Fig. 8 (b)), the cover film 9b2 is lowered (Fig. 8 (c)), and pressed from above with a plastic spreader 9b3 (Fig. 8 (d) )), The sample liquid is spread circularly and evenly and absorbed (FIG. 8 (e)). When the cold water soluble gel is solidified, it is stored in an incubator as it is, cultured at a predetermined temperature and time, and the number of colonies generated is counted.

  Advantages of using a film medium typified by Petrifilm (registered trademark) 9b are that it saves labor for producing the medium, saves time for discarding the medium, and saves space occupied in the incubator during the culture, By using the film medium for the viable cell count test, the time and materials for the viable count test can be saved significantly. In addition, since the film medium is thin, it is an important merit that it is easy to focus when observing colonies with a magnifying glass or a microscope.

  On the other hand, as a technical problem when the film medium is used for the viable cell count test, when an operator unfamiliar with the handling of the film medium performs the viable cell count test, when it is pressed with the spreader 9b3 from the top of the cover film 9b2, There is a problem that the gelled portion does not become a beautiful circle as in the case of using the conventional Petri dish 9a1, and a measurement error of the viable cell count occurs. In addition, the medium components outside the gelled portion pressed by the spreader 9b3 are discarded wastefully, leading to high costs.

  As a dry culture medium in which the gelled part has a beautiful circular shape and no waste of medium components, the medium part is circular from the beginning, and the medium part is surrounded by a frame having a sufficient height. A dry medium has been proposed.

  FIG. 9 is a diagram for explaining a sterile culture package disclosed in Patent Document 1, and FIG. 10 is a diagram for explaining a film medium with a pedestal disclosed in Patent Document 2.

  For example, as a dry medium having the above-described structure, in Patent Document 1, as shown in FIG. 9, a sterile culture package having a structure in which a dry medium is provided at the bottom of a cereal bottle and a sample solution is dropped onto the dry medium with an injection needle. 9c is disclosed. By using the aseptic culture package 9c disclosed in Patent Document 1, a beautiful circular culture part can be obtained in the same manner as the agar medium using the Petri dish 9a1, but on the other hand, the cost is reduced by using a cereal bottle. Become high. Another problem is that it is difficult to visually count the number of colonies due to the shape of the cereal bottle.

  As a dry culture medium having the above-described structure, in Patent Document 2, as shown in FIG. 10, a circular area to be a culture surface is surrounded by a convex circular pedestal 9d1 in the same form as a film culture medium. A pedestal film medium 9d is disclosed. According to the film medium with pedestal 9d disclosed in Patent Document 2, it is possible to form a beautiful circular gelled portion by dropping the sample solution into the circular pedestal 9d1 of the film medium with pedestal 9d. It becomes. However, since the culture medium components are applied to the entire surface of the base material of the film medium 9d with a pedestal, the medium components outside the circular pedestal 9d1 are wasted and the problem of high costs remains.

  In order to solve the problem of waste of medium components in the film medium 9d with a pedestal, the applicant of the present invention disclosed in Patent Document 3 a medium liquid coated sheet that is a sheet coated with a medium liquid (dispensed liquid in Patent Document 3). As for the manufacturing method, Patent Document 4 discloses a porous nozzle necessary for the manufacturing method disclosed in Patent Document 3, respectively.

  In the method for producing a medium solution coating sheet disclosed in Patent Document 3, a separation distance between a discharge surface of a porous nozzle composed of nozzles having a hole diameter of 0.9 mm to 1.6 mm and a substrate surface is set to 0.3 mm. -Dispensing liquid with a solid content of 20% to 50% at a rate of ~ 1.0mm is transferred to the base material surface so that the coating amount from the nozzle constituting the porous nozzle is 250g / m2 to 1050g / m2. It is a method of applying.

  FIG. 11 is a diagram for explaining the porous nozzle disclosed in Patent Document 4. As shown in FIG. The perforated nozzle 9e disclosed in Patent Document 4 is a nozzle required in the method for producing a medium solution coating sheet disclosed in Patent Document 3, and this perforated nozzle 9e is shown in FIG. It has a discharge surface with a bundle of thin nozzles

JP 2001-114339 A JP-T-2004-515236 JP 2013-55899 A JP 2013-51931 A

However, the following problems remain in the method for producing a medium-liquid-coated sheet using the porous nozzle 9e disclosed in Patent Document 4, and the mass production and production cost of the sheet coated with the medium liquid remain. The situation is difficult to reduce.
(1) Since the porous nozzle 9e of Patent Document 4 is a bundle of nozzles with small diameters, clogging occurs when the solvent of the medium solution volatilizes and the viscosity of the medium solution changes. Therefore, when the dispenser stops due to chocolate stop, adjustment, break, etc., clogging occurs, and the work cannot be resumed unless the perforated nozzle 9e is thoroughly cleaned.
(2) Since the porous nozzle 9e is a precision-processed product, it is relatively expensive, and an operation method in which the porous nozzle 9e that is clogged is replaced and discarded is not possible.

  Therefore, the present invention can apply a medium solution for forming a dry medium used for viable cell count inspection using a nozzle that can be manufactured at low cost, and further suppress the occurrence of clogging due to a change in the viscosity of the medium solution. An object of the present invention is to provide a method for applying a medium solution that can be used and a nozzle used in this method.

A first invention for solving the above-mentioned problem is to supply a medium solution for forming a dry medium used for viable cell count inspection to a porous nozzle whose discharge port is constituted by a sponge-like porous member having continuous pores. and, wherein the pores on the underside of the sponge-like porous member to eject the medium liquid, wherein said sponge-like porous member having the same shape of the porous nozzle to the substrate sheet to form said drying medium A method for applying a medium solution, comprising applying a medium solution.

A second aspect of the invention is a porous head required for the medium solution coating method described in the first aspect of the invention. The porous head has a medium solution flow path for forming a dry medium used for viable cell count inspection. And a nozzle body part having an enlarged chamber communicating with the medium liquid channel, and a sponge-like porous member having continuous pores disposed at the discharge port. And a perforated plate provided with a plurality of holes so as to uniformize the distribution of the culture medium supplied to the discharge port through the diameter-enlarging chamber of the nozzle body. Features. In the porous nozzle according to the second aspect of the invention, it is desirable that the discharge port portion be configured to be exchangeable.

According to the above-described present invention, since the sponge-like porous member is an inexpensive material, a medium solution for forming a dry medium used for viable cell count inspection can be applied using a nozzle that can be manufactured at low cost. If the porous nozzle can be manufactured at low cost, the clogged porous nozzle can be used in a disposable manner. Further, the sponge-like porous member is to have a continuous gas holes, the flow path of the medium fluid is 3-dimensional, the effect of clogging even after changing the viscosity of the medium liquid is less likely to occur is obtained.

The figure explaining the dispenser used for a culture-medium liquid coating method. The figure explaining a discharge valve. The figure explaining a porous nozzle. The figure explaining a base material sheet. The figure explaining the culture-medium liquid coating method. The figure explaining the viable count test using an agar medium. The figure explaining Petrifilm (trademark). The figure explaining the usage method of Petrifilm (trademark). The figure explaining the aseptic culture packaging body currently disclosed by patent document 1. FIG. The figure explaining the film culture medium with a base currently disclosed by patent document 2. FIG. The figure explaining the porous nozzle currently disclosed by patent document 4. FIG.

  From here, preferred embodiments of the present invention will be described. The following description is not intended to limit the scope of the present invention, but is provided to aid understanding.

  FIG. 1 is a diagram for explaining a dispenser 1 used in the medium liquid coating method according to the present embodiment. The dispenser 1 illustrated in FIG. 1 is an apparatus for applying a medium solution for forming a dry medium used for viable cell count inspection in a circular pedestal 7a provided on a base sheet 7 that forms a dry medium. is there.

  A dispenser 1 shown in FIG. 1 includes a pressure tank 5 filled with a medium for forming a dry medium used for viable cell count inspection, and a discharge valve 3 provided with a porous nozzle 2 for discharging the medium at the tip. And a triaxial moving mechanism 4 to which the discharge valve 3 is attached, and a controller 6 for controlling the application of the medium solution.

  The dispenser 1 can be classified into a flow rate control method and a volume metering method according to the control method, but the present invention does not ask the control method of the dispenser 1, and in FIG. 1, the control method of the dispenser 1 is a flow rate control method. More specifically, a system is adopted in which the medium liquid filled in the pressure tank 5 is pressurized with air and the discharge amount is controlled by opening and closing the flow path of the medium liquid.

  As the medium solution filled in the pressure tank 5, for example, a medium solution (dispensing solution) disclosed by the present applicant in Japanese Patent Application Laid-Open No. 2013-55898 can be used. The culture medium disclosed by the present applicant in JP2013-55898A contains 20% by mass to 40% by mass of solid content dispersed as particles, and the average particle size of the particles is 90 μm or less, preferably 65 μm or less. And a medium solution having a viscosity of 100 to 1200 cp.

  An air tube 8a extending from an air supply source is connected to the pressure tank 5 filled with the medium solution via a regulator 5a, and the medium solution filled in the pressure tank 5 is supplied by air supplied from the air supply source. It is configured to pressurize at a predetermined pressure. The pressure tank 5 is connected to the discharge valve 3 by a medium solution tube 8 b so that the medium solution filled in the pressure tank 5 can be supplied to the discharge valve 3. Further, the pressure tank 5 is provided with a stirring blade 5b for stirring the medium solution stored in the pressure tank 5 at a substantially central portion so that particles contained in the medium solution filled in the pressure tank 5 do not precipitate. The motor 5c for rotating the stirring blade 5b is provided at the upper part of the pressure tank 5.

  The three-axis moving mechanism 4 includes an X-axis moving mechanism 4a that moves the stage 4d in the X-axis direction, a Y-axis moving mechanism 4b that moves the stage 4d in the Y-axis direction, and a Z-axis moving mechanism that moves the stage 4d in the Z-axis direction. 4c is combined, and the stage 4d is configured to be movable in the XYZ-axis directions. In this embodiment, the stage 4d in which the discharge valve 3 having the porous nozzle 2 attached to the tip is installed is moved in the Z-axis direction. It is provided in the mechanism 4c.

  FIG. 2 is a view for explaining the discharge valve 3 with the porous nozzle 2 attached to the tip. The discharge valve 3 has a valve 3a for opening and closing the flow path of the medium liquid supplied to the porous nozzle 2, and the discharge valve 3 is connected to a tube 8b for the medium liquid extending from the pressure tank 5, and further discharges. An air tube 8 d for controlling the opening and closing of the valve 3 a of the valve 3 is connected, and the air tube 8 d is connected to the controller 6.

  3A and 3B are diagrams for explaining the porous nozzle 2 attached to the tip of the discharge valve 3. FIG. 3A is a diagram for explaining the structure of the porous nozzle 2, and FIG. It is a figure explaining the parts to do.

As shown in FIG. 3 (a), the porous nozzle 2 according to this embodiment is a porous head disclosed in Patent Document 4 already filed by the present applicant. The nozzle is changed from a sponge-like porous member 240 to a slight improvement.

As shown in FIG. 3B, the porous nozzle 2 according to the present embodiment includes a nozzle body 20, a porous plate 21, a ring-shaped seal packing 22, a mesh plate 23, and a sponge-like shape having continuous pores. The porous member 240 is composed of a discharge port portion 24 arranged at the discharge port.

  As shown in FIGS. 3A and 3B, the nozzle body 20 of the porous nozzle 2 has a medium liquid flow path 200 serving as a medium liquid flow path supplied from the pressure tank 5, a medium liquid flow. An enlarged chamber 201 communicating with the passage 200 is formed. Similarly to Patent Document 4, the diameter of the medium liquid flow path 200 formed in the nozzle body 20 is preferably 2 to 25 mm, and more preferably 4 to 8 mm. The diameter expansion chamber 201 formed in the nozzle body 20 is a cylinder having a diameter larger than that of the medium liquid flow path 200, and the shape of the diameter expansion chamber 201 is reversed when viewed from the discharge port side of the porous nozzle 2. A truncated cone may be used. In addition, the nozzle body 20 of the present embodiment is provided with a flange for joining to the discharge port 24, and as shown in FIG. Screwed to the outlet 24.

  As shown in FIG. 3A, the perforated plate 21 is a disk-like member disposed between the nozzle body 20 and the discharge port 24, and discharges through the diameter expansion chamber 201 of the nozzle body 20. The distribution of the medium solution supplied to the outlet 24 is made uniform so that the medium solution can be evenly supplied to the discharge port 24. In the present embodiment, the area of the porous plate 21 is set to be substantially the same as that of the discharge port 24, but the area of the porous plate 21 is more than the area of the discharge port of the discharge port 24 from the viewpoint of securing the flow rate of the medium solution. You can make it bigger.

  Similar to Patent Document 4, the porous plate 21 is provided with a plurality of holes 210 so that the distribution of the medium solution supplied to the discharge port portion 24 via the diameter expansion chamber 201 of the nozzle body portion 20 can be made uniform. Yes. The hole diameter of the hole 210 is preferably 0.1 to 5.0 mm / piece, more preferably 0.1 to 3.0 mm / piece, and 0.1 to 2.0 mm / piece. Is more preferred, and most preferred is 0.5 to 2.0 mm / piece. The density of the holes 210 is preferably 5 to 20 holes / cm 2, more preferably 5 to 16 holes / cm 2, and most preferably 8 to 16 holes / cm 2.

  The mesh plate 23 is a disk-like member disposed on the lower side of the perforated plate 21 and is provided for removing foreign substances in advance. As in Patent Document 4, in order to reduce the influence on the diffusion of the medium solution, the mesh of the mesh plate 23 should be changed from 20 mesh (aperture 0.850 mm) to 80 mesh (aperture 0.178 mm). Is preferred.

  The seal packing 22 is a ring-shaped member provided to prevent the culture medium from leaking from the joint between the nozzle body 20 and the discharge port 24 of the porous nozzle 2.

The discharge port portion 24 is a member joined to the nozzle main body portion 20, and the discharge port portion 24 is provided with a flange connected to the nozzle main body portion 20. Is formed with a sponge-like porous member 240 serving as a discharge port so as to close the hole. Similar to Patent Document 4, the diameter of the sponge-like porous member 240 used as the discharge port is the same as the diameter of the dry medium formed on the base sheet 7, preferably 20 to 100 mm, more preferably 30-70 mm. The arrangement in this embodiment, a sponge-like porous member 240 thickness of 10 mm, the porous member 240 partially protrude as sponge-like porous member 240 the lower surface of a sponge-like discharge port portion 24 doing.

The sponge-like porous member 240 means a material having continuous pores. Since the clogging pore diameter is smaller than the diameter of the particles contained in the medium solution of sponge-like porous member 240 is likely to occur, pore size of the sponge-like porous member 240 is included in the culture medium solution It depends on the diameter of the particles. For example, when the average particle diameter of the particles contained in the medium is 90 μm or less, the sponge-like porous member 240 having a pore diameter larger than the average particle diameter of the particles is selected. Regarding the porosity of the sponge-like porous member 240, if the porosity is small, the flow rate is insufficient. Therefore, the porosity of the sponge-like porous member 240 is preferably 50% or more. As such a sponge-like porous member 240, melamine foam (melamine sponge) can be used.

In the porous nozzle 2 of the present embodiment, the flange of the nozzle body 20 and the flange of the discharge port 24 are screwed so that the nozzle body 20 and the discharge port 24 can be separated from each other. This is to make it possible to easily replace 24. As in Patent Document 4, a multi-hole nozzle having a plurality of nozzles as discharge ports is a precision-processed product, so the price thereof is relatively high. However, the porous nozzle 2 of this embodiment is inexpensive. Since the sponge-like porous member 240 is used for the discharge port, it is possible to adopt an operation method in which the porous nozzle 2 (here, the discharge port portion 24) in which clogging has occurred is replaced and disposed of.

  From here, the culture medium coating method according to the present embodiment will be described while describing the controller 6.

  As shown in FIG. 1, the controller 6 is connected to an air tube 8c extending from an air supply source, and the controller 6 is connected to the discharge valve 3 via an air tube 8d.

FIG. 4 is a diagram illustrating the base sheet 7. The base material sheet 7 is a base material that forms a dry medium used for the viable cell count test, and the base material sheet 7 is provided with a multi-sided circular pedestal 7a using a hot melt resin or the like (here, 6-sided). Has been. The inner diameter of the circular pedestal 7 a formed on the base sheet 7 is the same as that of the sponge-like porous member 240 of the porous nozzle 2.

FIG. 5 is a diagram for explaining a medium solution coating method according to the present embodiment. The controller 6 activates the X-axis moving mechanism 4a and the Y-axis moving mechanism 4b of the three-axis moving mechanism 4 when the medium solution is applied to one of the circular pedestals 7a formed on the base sheet 7. After moving the porous nozzle 2 in the XY-axis direction so that the center point of the circular pedestal 7a to which the liquid is applied and the center point of the sponge-like porous member 240 of the porous nozzle 2 are aligned, The Z-axis moving mechanism 4c of the three-axis moving mechanism 4 is operated until the distance between the lower end and the base sheet 7 reaches the distance h (FIG. 5A). The distance h is preferably 0.3 mm to 1.0 mm.

Next, the controller 6 controls the air supplied to the discharge valve 3 to open the discharge valve 3 so that the medium solution filled in the pressure tank 5 is made porous through the discharge valve 3. When the medium solution is supplied to the nozzle 2 and pressurized in the medium solution channel 200 of the porous nozzle 2, the medium solution is discharged from the pores on the lower surface of the sponge-like porous member 240 (FIG. 5 ( b)).

  When a predetermined time elapses after the discharge valve 3 is opened, the controller 6 controls the air supplied to the discharge valve 3, and when the discharge valve 3 is closed, the medium liquid flow path 200 of the porous nozzle 2. Then, the medium solution is no longer pressurized, the discharge of the medium solution is stopped, and a certain amount of the medium solution is applied in the circular pedestal 7a of the base sheet 7 (FIG. 5C). The coating amount of the medium solution is preferably about 250 g / m 2 to 1050 g / m 2.

As described so far, by applying the medium solution using the porous nozzle 2 having the sponge-like porous member 240, the medium is the same as when using the porous nozzle disclosed in Patent Document 4. Although the liquid can be applied, the following new effects can be obtained by applying the medium liquid using the porous nozzle 2 having the sponge-like porous member 240.
Sponge-like porous member 240 because it has a continuous gas holes, the flow path of the medium fluid is 3-dimensional, clogging even after changing the viscosity of the medium liquid is less likely to occur.
Since the sponge-like porous member 240 is an inexpensive member, a disposable operation method of the clogged porous nozzle 2 can be achieved.

DESCRIPTION OF SYMBOLS 1 Dispenser 2 Porous nozzle 20 Nozzle main-body part 200 Medium liquid flow path 201 Expansion chamber 21 Porous plate 22 Seal packing 23 Mesh plate 24 Discharge port part 240 Sponge-like porous member 3 Discharge valve 3a Valve 4 Triaxial moving mechanism 5 Pressure tank 6 Controller 7 Base sheet 7a Circular pedestal 8a, c, d Air tube 8b Medium solution tube

Claims (3)

A medium nozzle for forming a dry medium used for viable cell count inspection is supplied to a porous nozzle having a discharge port formed of a sponge-like porous member having continuous pores, and from the pores on the lower surface of the porous member. A medium liquid coating method, comprising: discharging the medium liquid, and applying the medium liquid having the same shape as the porous member of the porous nozzle onto a substrate sheet forming the dry medium.
A culture medium flow path serving as a culture medium flow path forming a dry culture medium used for viable cell count inspection, a nozzle main body formed with an enlarged chamber communicating with the culture medium flow path, and the nozzle main body joined The distribution of the medium solution supplied to the discharge port portion through the discharge port portion having a sponge-like porous member having continuous pores arranged at the discharge port and the diameter expansion chamber of the nozzle body portion is made uniform. A porous nozzle comprising a porous plate provided with a plurality of holes as described above.
The porous nozzle according to claim 2, wherein the discharge port is configured to be exchangeable.

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