Ruler for culture dish

Abstract

To provide a ruler for culture dish which is capable of accurately drawing lines for partition on a rear face of a culture dish.SOLUTION: A circular ruler for culture dish comprises: an annular-shaped outer peripheral edge part having an outer diameter that fits a circular bottom face forming a rear face of a culture dish; an annular erected part which is formed in an annular shape along an outer peripheral edge of the outer peripheral edge part, and is erected from the outer peripheral edge part so as to come into contact with the outer peripheral side face of the culture dish in the case where the ruler is placed on the culture dish such that the outer peripheral edge part rides the circular bottom face; and a guide part which is arranged inside the outer peripheral edge part and has a linear or curved guide for guiding a writing instrument.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a ruler for culture dishes. [Background technology]

[0002] Culture dishes, also known as petri dishes or petri dishes, are used for culturing microorganisms such as bacteria (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Utility Model Application Publication No. 62-1599 Summary of the Invention [Problem to be solved by the invention]

[0004] The bottom surface of a culture dish may be divided into several sections. To divide the bottom surface of a culture dish, for example, lines for dividing the sections are drawn on the back of the culture dish with an oil-based pen, or a sticker with the lines printed on it is attached.

[0005] Stickers with lines printed on them are usually pre-made products. Therefore, it is difficult to freely divide the bottom of a culture dish. In addition, in the case of stickers, the required number of stickers must be secured in advance. On the other hand, with an oil-based pen, it is possible to freely divide the bottom of a culture dish. However, it is not easy to accurately draw lines on the back of a culture dish with an oil-based pen.

[0006] Therefore, the present application discloses a ruler for culture dishes that is capable of drawing division lines with high accuracy on the back side of a culture dish. [Means for solving the problem]

[0007] In order to solve the above problems, in the present invention, a circular annular upright portion is erected along the outer edge of a circular outer periphery portion having an outer diameter that matches the circular underside surface that forms the back surface of a circular culture dish, and a guide portion having a straight or curved guide for guiding a writing instrument is provided on the inside of the outer periphery portion.

[0008] In detail, the present invention is a ruler for circular culture dishes, comprising: a circular outer peripheral edge portion having an outer diameter that matches the circular underside that forms the back surface of the culture dish; an annular upright portion that is formed in a circular shape along the outer peripheral edge of the outer peripheral edge portion and that stands up from the outer peripheral edge portion so as to abut against the outer peripheral side surface of the culture dish when the ruler is placed on the culture dish so that the outer peripheral edge portion rests on the circular underside; and a guide portion that is positioned inside the outer peripheral edge portion and has a straight or curved guide that guides a writing instrument.

[0009] Such a ruler can be rotated precisely around the center of a circular culture dish, making it easy to draw rotationally symmetric lines, such as radial lines or grid lines, and therefore it is easy to draw lines that divide the culture dish.

[0010] The guide portion may have a guide hole that forms a guide. If the guide for guiding the writing tool is formed by the guide hole in this manner, the writing tool can be inserted into the guide hole to draw a line, so that the line that divides the culture dish can be easily drawn.

[0011] The guide portion has a plurality of guides arranged radially around the center point of the outer periphery. With such a ruler, it is possible to easily draw lines at equal angles to partition the culture dish.

[0012] The ruler may further include a mark for rotating the ruler relative to the culture dish and aligning the rotational position with a line drawn with a writing implement on the circular underside. With such a ruler, it is possible to easily draw lines at equal angles that divide the culture dish into smaller sections by rotating the ruler and aligning the mark with the line.

[0013] The guide portion may have a plurality of parallel guides at equal intervals. With such a ruler, it is possible to easily draw lines that divide the culture dish vertically and horizontally. Effect of the Invention

[0014] The above-mentioned ruler for culture dishes makes it possible to draw dividing lines on the back side of a culture dish with high precision. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is an external view of a ruler according to an embodiment. [Diagram 2] FIG. 2 shows how to place the ruler on the culture dish. [Diagram 3] FIG. 3 shows how to draw a line. [Figure 4] FIG. 4 shows a culture dish on which dividing lines are drawn. [Diagram 5] FIG. 5 is an external view of a ruler according to a first modified example. [Figure 6] FIG. 6 is an external view of a ruler according to a second modified example. [Figure 7] FIG. 7 is an external view of a ruler according to a third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described. The embodiment described below is one aspect of the present invention, and is not intended to limit the technical scope of the present invention.

[0017] Fig. 1 is an external view of a ruler 1 according to an embodiment. Fig. 1(A) shows a top view of the ruler 1, Fig. 1(B) shows a side view of the ruler 1, and Fig. 1(C) shows a bottom view of the ruler 1.

[0018] Ruler 1 is a ruler for drawing dividing lines with a writing implement on the back side of a circular culture dish, also known as a petri dish or a petri dish. For this reason, ruler 1 is shaped to fit the back side of a circular culture dish, making it possible to easily draw multiple dividing lines radially with high precision while it is placed against the back side of the culture dish.

[0019] That is, the ruler 1 has an annular outer peripheral edge 2 having an outer diameter that matches the circular underside that forms the back surface of a circular culture dish. Circular culture dishes, also called petri dishes or petri dishes, are commercially available in a variety of outer diameters. For this reason, it is preferable that rulers 1 are also prepared in a variety of outer diameters that match culture dishes of various sizes. However, the ruler 1 is not limited to a form in which multiple types are prepared to correspond to culture dishes of all sizes. The ruler 1 may have an outer peripheral edge 2 that matches the outer diameter of a diameter of 90 mm, which is relatively commonly used, for example.

[0020] Guide sections 3 are provided radially on the inside of the outer periphery 2. The guide sections 3 are sections that have linear guide holes 4 (an example of the "guide" as used herein) for guiding a writing implement. In the ruler 1 of this embodiment, three guide sections 3 are provided at 120 degree intervals so as to radially divide the inside of the outer periphery 2 into thirds around the center point of the ruler 1.

[0021] In addition, a mark 5 is provided on the inner peripheral edge of the outer peripheral edge portion 2. The mark 5 is provided on a 120-degree arc-shaped portion that is radially divided into three equal parts around the center point of the ruler 1 by the guide portion 3, and the mark 5 is provided on the arc-shaped portion. There are six in total, two on each side, dividing the area into thirds. This allows the user to use guide holes 4 to draw a line on the culture dish with a writing implement, then rotate ruler 1 so that mark 5 lines up with the drawn line, ultimately drawing lines that divide the culture dish into nine equal parts.

[0022] The ruler 1 also has an annular upright portion 6 formed in a circular ring shape along the outer periphery of the outer periphery portion 2. The annular upright portion 6 stands upright from the outer periphery portion 2 so as to abut against the outer periphery side of the culture dish when the ruler 1 is placed on the culture dish so that the outer periphery portion 2 rests on the circular underside of the culture dish. Therefore, when the ruler 1 is placed on the culture dish upside down, the outer periphery portion 2 rests on the circular underside of the culture dish, and further, the annular upright portion 6 abuts against the outer periphery side of the culture dish, so that the ruler 1 is fitted into the culture dish. This allows the user of the ruler 1 to easily rotate the ruler 1 by hand around the center point of the ruler 1 on the culture dish without displacing the ruler 1.

[0023] The height of the annular standing portion 6 may be such that the ruler 1 does not shift from the culture dish when it abuts against the outer circumferential side surface of the culture dish. The height of the annular standing portion 6 may be such that the ruler 1 can be easily removed from the culture dish. The height of the annular standing portion 6 may be, for example, within the range of 1 mm to 5 mm.

[0024] FIG. 2 is a diagram showing how to place the ruler 1 on the culture dish P. FIG. 2(A) shows how to place the ruler 1 when viewed from diagonally above the ruler 1. FIG. 2(B) shows how to place the ruler 1 when viewed from diagonally below the ruler 1. The ruler 1 is used to draw lines on the circular lower surface P1 that forms the back surface of the culture dish P. Therefore, when placing the ruler 1 on the culture dish P, as shown in FIG. 2, the culture dish P is placed upside down on the table. In other words, the culture dish P is placed on the table with the circular lower surface P1 facing upwards and the bottom surface P3 facing downwards.

[0025] In this position, ruler 1 is placed on culture dish P, which is placed on a table. When ruler 1 is placed on culture dish P, outer peripheral edge 2 rests on circular lower surface P1, and annular erected portion 6 abuts against outer peripheral side surface P2 over the entire circumference. Therefore, ruler 1 is aligned and rotatable around its center point.

[0026] FIG. 3 shows how to draw lines. When using the ruler 1 to draw demarcation lines on the circular underside P1, insert the tip of the oil-based pen M into the guide hole 4 and slide it along the longitudinal direction of the guide hole 4 as shown in FIG. 3(A). This draws straight demarcation lines L on the circular underside P1. After drawing three demarcation lines L using each of the three guide holes 4 on the ruler 1, rotate the ruler 1 so that the mark 5 is aligned with the demarcation line L as shown in FIG. 3(B). Then, slide the tip of the oil-based pen M along the guide hole 4 again to draw the demarcation line L as shown in FIG. 3(C). By repeating these steps, a total of nine demarcation lines L are drawn on the circular underside P1.

[0027] Fig. 4 shows a culture dish P on which a dividing line L is drawn. Fig. 4(A) shows a view of the culture dish P on which the dividing line L is drawn, as viewed obliquely from above. Fig. 4(B) shows a view of the culture dish P on which the dividing line L is drawn, as viewed obliquely from below.

[0028] By using the ruler 1, nine division lines L are drawn radially at equal angles on the circular bottom surface P1 as shown in FIG. 4. Since the culture dish P is usually transparent or semi-transparent, the division lines L drawn on the circular bottom surface P1 are visible from the bottom surface P3 side as shown in FIG. 4(A). This allows the user to perform various tasks such as culturing bacteria on the culture dish P divided by the division lines L. Such tasks include, for example, drug susceptibility tests, measuring the diameter of colonies, and identifying the position of colonies.

[0029] As described above, the ruler 1 makes it easy to draw the dividing lines L radially at equal angles on the circular underside P1. For example, if a sticker with the dividing lines printed on it is attached to the circular underside P1, it is necessary to prepare ready-made stickers with the desired number of divisions each time, which increases costs and risks running out of stock. In this regard, the ruler 1 of this embodiment makes it easy to draw the dividing lines L on the circular underside P1 with oil pen M with high accuracy, and is free from the increased costs and risks of running out of stock that occur when stickers are used.

[0030] Furthermore, the ruler 1 of the above embodiment can be rotated around the center point of the culture dish P, so it is possible to always draw beautiful radial demarcation lines L at equal angles. Moreover, while the demarcation lines L are being drawn using the ruler 1, the ruler 1 is fitted into the culture dish P by the annular upright portion 6, so the ruler 1 is fixed in position relative to the culture dish P without shifting. This makes it possible to draw the demarcation lines L accurately.

[0031] Moreover, with the above ruler 1, it is not only possible to divide the circular underside P1 into thirds by drawing only three demarcation lines L on the circular underside P1, but also possible to divide the circular underside P1 into nine equal parts by drawing nine demarcation lines L on the circular underside P1. Also, by preparing a ruler 1 in which the positional relationship of the mark 5 to the outer periphery 2 is changed, it is possible to divide the circular underside P1 into a number of parts other than thirds or nine parts.

[0032] Moreover, the ruler 1 of the above embodiment may be modified, for example, as follows.

[0033] <Variation 1> Fig. 5 is an external view of ruler 1A according to the first modified example. Fig. 5(A) shows a top view of ruler 1A, Fig. 5(B) shows a side view of ruler 1A, and Fig. 5(C) shows a bottom view of ruler 1A. In ruler 1A according to this first modified example, the same components as those in the above embodiment are given the same reference numerals and detailed descriptions thereof will be omitted.

[0034] In the ruler 1A of the first modification, as shown in FIG. 5, four guide parts 3 are provided at 90 degree intervals so that the guide holes 4 radially divide the inside of the outer peripheral edge part 2 into four equal parts around the center point of the ruler 1. This makes it possible to draw the dividing lines L that divide the circular lower surface P1 into four equal parts by using the ruler 1A to draw the dividing lines L with an oil-based pen M on the circular lower surface P1. In addition, in the ruler 1A of the first modification, the marks 5 are provided in a total of four, one on each of the 90-degree arc-shaped parts that are radially divided into four equal parts around the center point of the ruler 1A by the guide parts 3, so as to divide the arc-shaped parts into two equal parts. This makes it possible to draw the dividing lines L that divide the circular lower surface P1 into eight equal parts by using the ruler 1A to draw the dividing lines L with an oil-based pen M on the circular lower surface P1, and then rotating the ruler 1A so that the marks 5 are aligned with the drawn dividing lines L.

[0035] <Variation 2> Fig. 6 is an external view of ruler 1B according to the second modified example. Fig. 6(A) shows a top view of ruler 1B, Fig. 6(B) shows a side view of ruler 1B, and Fig. 6(C) shows a bottom view of ruler 1B. In ruler 1B according to the second modified example, the same components as those in the above embodiment are given the same reference numerals and detailed descriptions thereof are omitted.

[0036] In ruler 1B of this second modified example, as shown in FIG. 6, five guide sections 3 are provided at 72 degree intervals so that guide holes 4 radially divide the inside of outer peripheral edge 2 into five equal parts around the center point of ruler 1. This makes it possible to use ruler 1B to draw division lines L on circular underside P1 with oil-based pen M, thereby drawing division lines L that divide circular underside P1 into five equal parts. Also, in ruler 1B of this second modified example, five marks 5 are provided, one on each of the 72 degree arc-shaped parts that are radially divided into five equal parts around the center point of ruler 1B by guide sections 3, so as to divide the arc-shaped parts in half. This makes it possible to use ruler 1B to draw division lines L on circular underside P1 with oil-based pen M, and then rotate ruler 1B so that mark 5 aligns with the drawn division lines L, resulting in a total of five marks 5. Ultimately, it becomes possible to draw dividing lines L that divide the circular underside P1 into 10 equal parts.

[0037] <Variation 3> Fig. 7 is an external view of a ruler 1C according to a third modified example. Fig. 7(A) shows a top view of the ruler 1C, Fig. 7(B) shows a side view of the ruler 1C, and Fig. 7(C) shows a bottom view of the ruler 1C. In the ruler 1C according to this third modified example, the same components as those in the above embodiment are given the same reference numerals and detailed descriptions thereof are omitted.

[0038] In the ruler 1C of the third modified example, as shown in FIG. 7, the guide portion 3 is not formed radially, but is formed to fill the entire area inside the outer peripheral edge portion 2. Also, the markings 5 ​​are omitted. The guide holes 4 are provided in the guide portion 3 in a number of straight lines (9 holes) arranged in parallel. This makes it possible to draw the dividing lines L that divide the circular lower surface P1 at equal intervals by using the ruler 1C to draw the dividing lines L on the circular lower surface P1 with an oil pen M. It is also possible to draw the dividing lines L that divide the circular lower surface P1 vertically and horizontally by rotating the ruler 1C 90 degrees and then using the ruler 1C to further draw the dividing lines L on the circular lower surface P1 with an oil pen M.

[0039] <Other Modifications> In the above embodiment and each modified example, the guide hole 4 is linear, and serves as a ruler for drawing radial or lattice-like division lines in rotational symmetry. However, in the above embodiment and each modified example, the guide hole 4 may be curved. Even if the guide hole 4 is curved, it is possible to draw rotationally symmetric lines. In addition, the guide for guiding the oil-based pen M in a linear or curved line is not limited to the shape of the guide hole 4 formed by a hole, and may be formed by a portion other than a hole, such as the edge of the guide portion 3, for example.

[0040] In addition, the above-described embodiment and each modified example can be modified as appropriate without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0041] 1, 1A, 1B, 1C · Ruler 2. Outer periphery 3. Guide section 4 Guide hole 5. Landmarks 6. Circular upright section P··Culture dish P1 Circular bottom surface P2...outer side P3...bottom M··Oil-based pen L··Landmark

Claims

1. A ruler for circular culture dishes, A circular outer peripheral edge portion having an outer diameter that matches the circular lower surface that forms the back surface of the culture dish; a ring-shaped upright portion that is formed along the outer periphery of the outer periphery portion and stands upright from the outer periphery portion so as to abut against the outer periphery side surface of the culture dish when the ruler is placed on the culture dish so that the outer periphery portion rests on the circular lower surface; A guide portion is disposed inside the outer circumferential edge portion and has a linear or curved guide for guiding a writing instrument. Ruler for culture dishes.

2. The guide portion has a guide hole that forms the guide. A ruler for a culture dish according to claim 1.

3. The guide portion has a plurality of guides radially arranged around a center point of the outer circumferential edge portion.

3. A ruler for a culture dish according to claim 1 or 2.

4. Further provided is a mark for rotating the ruler relative to the culture dish to align the rotational position with a line drawn with a writing tool on the circular lower surface. A ruler for a culture dish according to claim 3.

5. The guide portion has a plurality of the guides arranged in parallel at equal intervals.

3. A ruler for a culture dish according to claim 1 or 2.

Images