6 Microscope of the experiments
Microscopic experiments are one of the best experiments to bring children to science. This page introduces various ways to use it, but I would like you to work on it yourself, such as a glass ball microscope, to understand the principle.
Experiment 1: Simple micrometer
You may be wondering how big the object you are observing with a microscope. You can measure it with a micrometer, but it costs several thousand yen per set , and it takes an hour for junior high school students to teach how to handle it. Therefore, use a ruler to grasp the approximate size of the sample.
you need : Ruler, microscope
First, look at the ruler at low magnification. When it is 100 times, the diameter of the field of view is a little over 1 mm and 1.3 to 1.4 mm. Be sure to measure for each microscope you use. It depends on the microscope. The photo on the right is an onion cell. Since about 10 cells are lined up side by side, the length of one cell is about 0.13 mm. It will be about 130 μm (this unit of μm is also difficult for junior high school students).
At 100 times, you can see up to a diameter of 1 mm. Then, at 400 times, the diameter becomes 1/4 of that. Is the basis.
Experiment 2: Three-dimensional effect by epi-illumination
It would be nice to have a binocular stereomicroscope, but when you don't have one, you can see it three-dimensionally with an ordinary microscope. This is called the epi-illumination method. Close the squeeze completely and shine light from above as shown in the picture below.
Light comes from above, creating shadows. Therefore, I feel a three-dimensional effect. The next picture is a coin. Doesn't it look like an ancient ruin or something? Next to it is a cloth. The fibers look very good. Suitable for observing insects and plants.
Experiment 3: Handmade polarizing microscope
I would like to show the rock preparation to the students once using a polarizing microscope. All you need is a polarizing plate (8 cm square, several hundred yen)! The original use of a polarizing microscope is to identify the composition of rocks and to investigate the strain of the crystal structure of plastics. Here, we will only say that the color changes depending on the type of crystal and the difference in making.
you need : Polarizing plate, rock preparation, microscope
Cut one polarizing plate into a circle. Put it in the eyepiece. Place the other one under the rock preparation, and then rotate the eyepiece while looking under a microscope. Of course, a more decent microscope is needed to identify minerals. However, isn't it enough to experience the mechanism of a polarizing microscope?
Experiment 4: Handmade stain (a substitute for carmine acetate that can be made for 200 yen)
It is a staining solution necessary for observing cells, but a carmine acetate solution costs about 4000 yen for 50 ml. It would be nice to have it on hand, but this time I will introduce a very inexpensive stain.
Dissolve the red color of food coloring in food vinegar. Just add a small amount to 100 ml of vinegar. This is enough for student experiments. If there are fine suspended matter, heat and dissolve and filter.
Food coloring is also available in other countries. The food coloring used in Africa stains the cytoplasm over time. The photo on the left turned red after this. It was not suitable. Red No. 102 is recommended because it costs about 100 yen per bottle.
The mechanism of dyeing occurs when substances are electrically attracted to each other. This dye is a family of basic dyes and has positive electricity in aqueous solution. Since the nucleus and chromosomes have negative electricity, they are dyed red. Since the component of vinegar is acetic acid, it also helps to fix the details. Very convenient.
Experiment 5: Let's take care of the microscope
It is a microscope that must be a biological experiment. However, sometimes you can't afford the maintenance budget and throw away your old microscope. What a wasteful story! It can be used with a little care ... I will talk about simple care.
First, clean the lens. Use a blower to remove dust. Sticky stains can be scraped off with a toothpick. If you have a piece of paper to wipe the lens, wrap it around a toothpick and wipe it from the inside in a spiral. Soak in ethanol and wipe further. Both eyepiece and objective. The eyepiece may be disassembled. I think it is better not to disassemble the objective lens. If there are many parts and you assemble them incorrectly, you will not be able to use them.
If the stage moves under its own weight, occupy both coarse-moving screws clockwise together.
Experiment 6: Handmade, smartphone microscope camera (digital camera)
you need : Double-sided tape such as plastic plate, film case, etc.
For micrographs, prepare a tube that fits the lens barrel and fix the smartphone. The film case is easy to use, so please take advantage of it.
Make a hole in the plastic plate and hollow out the film case. Align the lid of the film case with the hole in the plastic plate and attach it. Attach the cylinder there. Stick double-sided tape to fix your smartphone. It is not bulky if you remove the film case tube when not in use.
When shooting, shoot in close contact. Recent smartphones have better resolution than digital cameras, so you can take very good pictures. In the case of a digital camera, insert a cylinder that fits the aperture of the lens, such as a PET bottle cap, and shoot as it is.