JPH0695927B2 - Medium forming tool - 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 forming tool for forming a medium for testing microorganisms.

[0002]

2. Description of the Related Art Conventionally, in the inspection of microorganisms, an agar medium is formed on a petri dish or the like, and the microorganisms are cultured and observed in the medium. Then, this type of agar medium is formed as follows. That is, first, a sample solution containing microorganisms is dispensed into a petri dish, and a standard agar medium which has been previously sterilized under high pressure and kept at about 50 ° C. is poured into the petri dish. Immediately after that, the sample solution and the medium are sufficiently mixed so that they are well mixed, and then the medium is allowed to stand until completely solidified.

However, in order to sterilize the agar medium under high pressure, a special device such as an autoclave is required. Also,
The above method requires a large amount of glass equipment such as a petri dish and a flask for heating the medium. Therefore, it has conventionally been necessary to install a special inspection room for microbiological inspection. Furthermore, in order to cultivate microorganisms satisfactorily, complicated work from sample liquid dispensing to pour must be done satisfactorily within a predetermined time, and in order to uniformly pour the sample liquid into the medium, Also required skill. Therefore, for microbiological tests using medium,
Specialized techniques for medium formation were required.

Therefore, there has been considered a method of directly infiltrating a sample solution into a filter paper (for example, "Sancoritep", trade name: manufactured by Sun Kagaku Co., Ltd.) that has been soaked in a culture medium and dried to culture the microorganism. In this method, the culture medium is dissolved by infiltrating the sample solution into the filter paper, and the microorganisms in the sample solution grow using the dissolved culture medium as a nutrient.

A method of culturing a microorganism by immersing a thin agar medium (for example, "Food Plate", trade name: Nissui Pharmaceutical Co., Ltd.) in a sample solution has also been considered. In this method, the agar medium is once immersed in the sample solution and pulled up, so that the microorganisms in the sample solution adhere to the surface and grow.

[0006]

However, in the method using the filter paper in which the culture medium is impregnated, when proliferating motile microorganisms, colonies due to the microorganisms are not easily formed. That is, unlike the agar medium, the filter paper permeated with the sample solution allows the microorganisms to move almost freely through it. Therefore, even if the microorganism grows, it does not form a settlement. Further, with this method, it was difficult to uniformly permeate the sample solution containing the microorganisms throughout the filter paper. For this reason, even if a colony of microorganisms is formed, it is difficult to determine the exact number of microorganisms due to overlapping of the colonies.

In the method of immersing the agar medium in the sample solution, the number of microorganisms attached to the agar medium does not exactly correspond to the number of microorganisms in the sample solution. For this reason, this method can detect only the tendency that the number of microorganisms is large or small. Therefore, the present invention has been made for the purpose of providing a medium forming tool capable of easily forming a medium in which microorganisms in a sample solution are uniformly dispersed.

[0008]

The present invention, which has been made to achieve the above object, has at least one of the following features:
A pair of flat plates that can face each other at a small interval and swell by absorbing water
Formed by mixing a gelling water-absorbing substance and a culture medium,
A gist of a culture medium forming tool, comprising: a water-absorbent mixture applied to a surface of at least one of the flat plates facing the other flat plate.

[0009]

According to the present invention thus constructed, the medium is formed by a simple operation in which the pair of flat plates are opposed to each other with a slight gap enough to cause capillary action and the sample solution is injected into the gap. can do. By doing so, the sample solution is uniformly diffused between the pair of flat plates due to the capillary phenomenon.
Further, the water-absorbent mixture applied to at least one of the flat plates absorbs the sample liquid and swells and gels. As a result, a medium in which the microorganisms in the sample solution are uniformly dispersed is formed in the gap between the pair of flat plates.

Further, in the present invention, the medium can be formed simply by dispensing the sample solution on one of the flat plates and stacking the other flat plate on the flat plate with the sample solution interposed therebetween. Also in this case, the sample solution is uniformly diffused through the gap between the pair of flat plates by the capillary phenomenon, and similarly, a medium in which the microorganisms in the sample solution are uniformly diffused is formed.

Furthermore, since at least one of the flat plates is transparent, microorganisms can be observed from the transparent side in any of the above cases.

[0012]

Embodiments of the present invention will now be described with reference to the drawings. 1 is a plan view showing the medium forming tool 1 of the first embodiment, FIG. 2 (A) is a sectional view taken along line AA of the medium forming tool 1, FIG.
(B) represents the BB line sectional view of the culture medium forming tool 1, respectively.

As shown in the drawing, the culture medium forming tool 1 has a rectangular shape, and a pair of flat plates 3 and 5 facing each other with a slight gap between them so that capillary action occurs, and the periphery of the flat plates 3 and 5. And a spacer 7 sandwiched between the flat plates 3 and 5. Each of the flat plates 3 and 5 is made of transparent hard vinyl chloride, and the spacer 7 is made of soft vinyl chloride. Further, the spacer 7 is divided at the center of one short side of the flat plates 3 and 5, and an opening 9 is formed in this portion. Further, a large number of screws 11 arranged along a pair of long sides of the flat plates 3, 5 are sequentially penetrating the flat plate 3, spacer 7, and flat plate 5, and the flat plate 3, spacer 7, and flat plate 5 are It is tightly fixed by this screw 11.

A water-absorbent mixture 13 formed by mixing a water-absorbent substance and a culture medium is applied to the surfaces of the flat plates 3 and 5 which face each other. Here, carrageenan was used as the water-absorbing substance, and its amount was adjusted so that when the flat plates 3 and 5 were filled with water, the flat plates 3 and 5 were swollen and gelled. A mixture of peptone, yeast extract, and glucose was used as the culture medium, and when the plates 3 and 5 were filled with water, the weight% of the water was 0.5%, 0.25%, and 0.1%, respectively. Each amount was adjusted so that a so-called standard medium was formed.

In the medium forming tool 1 of this embodiment having the above-mentioned structure, the medium can be formed as follows. That is, a sample solution containing microorganisms (for example, a small amount of Escherichia coli dispersed in sterile physiological saline) is sucked into a sterilized syringe and injected through the opening 9 between the plates 3 and 5. Then, the sample solution is uniformly diffused between the flat plates 3 and 5 by the capillary phenomenon. Following this, the water-absorbent mixture 13 swells and gels, forming a medium between the flat plates 3 and 5. After sealing the opening 9 with an adhesive tape and allowing it to stand until the medium is completely solidified, it becomes possible to culture and observe microorganisms.

In this embodiment, since the pair of flat plates 3 and 5 are made of transparent material, the medium can be placed on the microscope together with the medium forming tool 1 to observe the microorganisms. Further, since the sample solution uniformly diffuses between the flat plates 3 and 5 due to the capillary phenomenon, the microorganisms similarly diffuse uniformly between the flat plates 3 and 5. Therefore, it is possible to prevent the settlements from overlapping with each other and to determine the accurate number of microorganisms.

Further, in this embodiment, the medium can be easily formed by injecting the sample solution through the opening 9. Therefore, it is not necessary to install a special inspection room or acquire specialized skills for the microbiological examination, and anyone can easily perform the microbiological examination.

In the above embodiment, the flat plate 3, the spacer 7 and the flat plate 5 are tightly fixed by the screws 11, but various methods of tightly fixing these members can be considered. For example, they may be adhered by an adhesive, may be sandwiched by clips, or may be welded to each other. Further, in the above embodiment, the flat plates 3 and 5 are formed in a rectangular shape, but they can be formed in various shapes such as a circular shape.

Further, although the spacer 7 is divided to form the opening 9 in the above-mentioned embodiment, the spacer 7 is divided into the flat plates 3 and 5.
The sample liquid may be injected by inserting the injection needle into the spacer 7 continuously on the entire circumference. Further, in the above embodiment, the flat plate 3 is formed by the spacer 7 and the adhesive tape.
5 is sealed, but if the sample liquid diffused between the flat plates 3 and 5 has a sufficient surface tension, these sealing members may not be provided.

Furthermore, in the above-mentioned embodiment, the water-absorbent mixture 13 is applied to both the flat plates 3 and 5, but it may be applied to only one of them, and in this case the same action and effect can be obtained. . Next, FIG. 3 is a cross-sectional view showing the medium forming tool 21 of the second embodiment. The medium forming tool 21 of the present embodiment includes a circular glass petri dish 23 and a bottom surface 23 a of the petri dish 23.
A thin soft vinyl chloride spacer 25 formed continuously along the circumference and a transparent hard vinyl chloride drop lid 27 having a radius smaller than the inner diameter of the petri dish 23 and larger than the inner diameter of the spacer 25 are provided. Also, the bottom surface 23
The above-described water-absorbent mixture 13 is applied to the portion of the inner side of the spacer 25 of a. Further drop lid 2
A lid knob 27a is provided at the center of 7 and the petri dish 23 is covered with a petri dish lid 29 to prevent contamination.

In the culture medium forming tool 21 thus constructed, when the dropping lid 27 is arranged on the spacer 25 as shown in the figure, the lower surface of the dropping lid 27 and the inner wall of the bottom surface 23a correspond to the thickness of the spacer 25. Face each other with a slight gap. It should be noted that this interval is set in advance to such an extent that capillary action occurs. Therefore, when the sample liquid is dispensed on the bottom surface 23a and the drop lid 27 is arranged on the spacer 25,
The sample liquid uniformly diffuses between the bottom surface 23a and the dropping lid 27 due to the capillary phenomenon. Therefore, it is possible to easily form a medium in which the microorganisms in the sample solution are uniformly dispersed. Therefore, it becomes possible to prevent the settlement of the microorganisms from overlapping with each other and to accurately determine the number of the microorganisms.

In the above embodiment, the drop lid 27
And the bottom surface 23a correspond to a pair of flat plates. In addition, in the above-described embodiment, the dropping lid 27 and the bottom surface 23 are provided by the spacer 25.
Although a and a are made to face each other with a slight gap therebetween, like the culture medium forming tool 31 of the third embodiment illustrated in FIG. 4, the drop lid 37 engages with the edge portion 23b of the petri dish 23. 37
a is formed, and by this engagement, the drop lid 37 and the bottom surface 23 are formed.
You may maintain the space | interval with a. Further, when the sample liquid dispensed on the bottom surface 23a has a sufficient surface tension, there is no need to particularly provide means for maintaining the distance between the dropping lid 27 and the bottom surface 23a. In this case, the distance between the drop lid 27 and the bottom surface 23a is a predetermined distance determined by the weight of the drop lid 27 and the surface tension of the sample liquid. Also, when the water-absorbent mixture 13 is applied to a flat plate having a sufficient area instead of the petri dish 23, and the sample solution is dispensed on the drop cover 27 to form a stack, the space between the flat plate and the drop cover 27 is also reduced. It is held at a predetermined interval similarly determined. In such a case, the sample liquid is uniformly diffused in a predetermined range determined by the weight of the dropping lid 27 and the surface tension of the sample liquid, and the same operation as in each of the above embodiments
The effect is obtained.

Further, in each of the above embodiments, the flat plate 3 and the flat plate 5 as a pair of flat plates, or the bottom surface 23a and the drop lids 27 and 37 are all made of a transparent material, but either of the pair of flat plates is used. Only one may be opaque. In this case, microorganisms can be observed from the transparent side. When a microorganism produces a pigment, the microorganism can be more easily observed by coloring one of the pair of flat plates, for example, white or the opposite color of the pigment. Further, although the medium is formed of carrageenan in each of the above-mentioned examples, the present invention can be applied to a medium composed of various materials such as gelatin.

Next, an experimental example for demonstrating the effect of the above embodiment will be described. The experiment was conducted as follows. First, the medium forming tool 21 of the second embodiment was prepared in which the inside diameter of the dish 23 was 9 cm, the inside diameter of the spacer 25 was 6 cm, and the wall thickness of the spacer 25 was 0.5 mm. Next, 1 ml of a sample solution in which a small amount of Escherichia coli was dispersed in sterile physiological saline was dispensed to the medium forming tool 21, and the medium was formed by the method described above.

On the other hand, as a comparative example, 1 ml of the above sample solution was dispensed into a petri dish having an inner diameter of 6 cm, and immediately about 5 ml of standard agar medium cooled to 45 ° C. was poured and poured. Subsequently, this was left standing and cooled to form a medium. Subsequently, the respective culture media of Examples and Comparative Examples were kept at 35 ° C. for 24 hours to culture Escherichia coli, and the grown colonies were counted. Results of repeating this experiment 10 times for each example. The average number of colonies per ml of the sample solution was 157 in the example and 153 in the comparative example, showing almost no difference. From the results of this experiment, in the medium forming tool 21 of the second embodiment, the degree of dispersion of E. coli is almost the same as that of the conventional method, although the medium forming work is dramatically simplified as compared with the conventional method. I know there isn't.

Therefore, in the medium forming tool 21, a medium in which the microorganisms in the sample solution are uniformly dispersed can be easily formed without installing a special inspection room for the inspection of microorganisms or acquiring specialized techniques. It has been proved that you can do it.
In addition, the effect can be proved also in other examples by similar experiments.

[0027]

As described above in detail, in the medium forming device of the present invention, the sample solution is diffused through the gap between the pair of flat plates by the capillarity to form the medium in which the microorganisms in the sample solution are uniformly diffused. be able to. Moreover, in order to form the medium, a pair of flat plates are made to face each other with a slight gap, and the sample solution is injected into the gap, or the sample solution is dispensed on one of the flat plates, It suffices to perform a simple operation such that the other flat plate is laminated on top with the sample liquid sandwiched therebetween.
Further, the microorganisms in the formed medium can be easily observed from the side where the transparent plate is arranged.

Therefore, by using the present invention, it is possible to easily prepare a medium in which the microorganisms in the sample solution are uniformly dispersed, without installing a special inspection room for the microorganism inspection or acquiring a specialized technique. Can be formed. Also, because of this, it is possible to prevent overlapping of settlements and to determine the exact number of microorganisms.

[Brief description of drawings]

FIG. 1 is a plan view showing a culture medium forming tool according to a first embodiment.

FIG. 2 is a cross-sectional view showing the culture medium forming tool of the first embodiment.

FIG. 3 is a cross-sectional view showing a culture medium forming tool of a second embodiment.

FIG. 4 is a cross-sectional view showing a culture medium forming tool of a third embodiment.

[Explanation of symbols]

1, 21, 31 ... Medium forming tool 3, 5 ... Plate
7, 25 ... Spacer 13 ... Water-absorbent mixture 23 ... Petri dish 2
7, 37 ... Dropper

Claims (1)

[Claims] 1. A pair of flat plates, at least one of which is transparent and can be opposed to each other at a slight interval, and a water-absorbing substance that swells and gels by absorbing water and a culture medium are mixed together, and at least one of them is formed. And a water-absorbing mixture applied to the surface of the flat plate of the other plate facing the other flat plate.