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Use and daily maintenance of biological microscope

1. How to use low power lens?

(1) Take out and place the microscope

The biological microscope is usually stored in the cabinet or box. When it is used, take it out of the cabinet, hold the arm tightly with the right hand, hold the base with the left hand, and place the microscope on the experimental platform in front of the left shoulder. The rear end of the base should be 1-2 inches away from the table, which is convenient for sitting operation.

(2) Aim at light

Move the rotator with the thumb and middle finger (do not move the objective lens by hand) to align the low-power lens with the through-hole of the lens platform. Open the aperture, raise the light collector, turn the reflector to the light source. Then observe with the left eye on the eyepiece (the right eye is open), and adjust the direction of the reflector until the light in the field of vision is uniform and bright.

(3) Placing slide specimen

Take a slide specimen and place it on the platform. Make sure that the side of the slide with the cover is facing up. Please do not put it upside down. Clamp it with the spring clip of the slide pusher, and then rotate the screw of the slide pusher to adjust the position to be observed to the center of the through-hole.

(4) Adjust the focal length

Turn the coarse adjuster counterclockwise with your left hand to make the stage slowly rise to about 5mm from the objective lens to the specimen piece. Pay attention not to observe on the eyepiece when raising the stage. Be sure to watch the stage rise from the right side to avoid excessive rise, causing damage to the lens or specimen. Then, open both eyes simultaneously, observe with the left eye on the eyepiece, and slowly turn the coarse adjuster clockwise with the left hand to make the stage slowly descend until a clear object appears in the field of vision.

If the object image is not in the center of the field of vision, adjust the slide pusher to the center. Suppose the brightness in the field of vision is not suitable. It can be adjusted by raising and lowering the position of the light collector or the size of the aperture. Suppose the stage has dropped more than the working distance (> 5.40mm), and no object image is seen when adjusting the focal length. In that case, it indicates that the operation has failed, so it should be operated again. Do not raise the stage rashly and blindly.

2. How to use high magnification lens?

(1) Choose a good target

We must first adjust the parts to be further observed to the center under the low power mirror, and adjust the object image to the clearest degree at the same time, then we can carry out the observation under the high power mirror.

(2)Nosepiece

Rotate the converter to replace the high-power lens. When converting the high power lens, rotate slowly, and observe from the side (to prevent the high power lens from colliding with the glass). If the high-power lens touches the glass, it means that the focal length of the low power lens is not adjusted properly, so it should be operated again.

(3) Adjust the focal length

After the high power lens is converted, use the left eye to observe on the eyepiece. At this time, you can generally see an unclear object image. You can move the screw of the fine adjuster counterclockwise about 0.5-1 turn to obtain a clear object image (do not use the coarse adjuster!)

If the brightness of the field of vision is not suitable, the light collector and aperture can be used to adjust it. Suppose the slide specimen needs to be replaced. In that case, the coarse adjuster must be turned clockwise (not in the wrong direction) to make the mirror table lower; then, the slide specimen can be removed.

3. How to use the oil lens of a biological microscope

(1) Before using the oil lens, it is necessary to observe through the low and high power lens and then move the part to be further magnified to the center of the field of vision.

(2) Raise the light collector to the highest position and open the aperture to the maximum.

(3) Turn the converter to make the high-power lens leave the through-hole, add a drop of asphalt on the glass slide of the part to be observed, and then slowly turn the oil mirror. When changing the oil mirror, horizontally look at the distance between the lens and the glass slide from the side. The lens can be immersed in the oil without crushing the glass slide.

Biological microscope is used to observe and study biological sections, biological cells, bacteria, living tissue culture, liquid precipitation, etc., as well as other transparent or translucent objects, powders, fine particles, and other objects. Its regular use is inseparable from routine maintenance, including:

The biological microscope should be placed in a dry and clean room to avoid mildew of optical parts, rust of metal parts, and dust. After using the microscope:

        ● Please put it back into the box (cabinet).

        ● Cover it with a glass cover or plastic cover.

        ● Put in the dry agent.


A biological microscope should not be put together with corrosive acids, reducing chemicals, or highly volatile chemicals to avoid corrosion and shorten service life. In principle, when observing the specimen containing liquid, it is generally necessary to cover the cover glass. If the liquid contains acid, alkali, and other corrosive chemicals, the surrounding of the cover glass should be sealed with paraffin or vaseline and then observed. However, this kind of reagent is often used in the microscopic identification of traditional Chinese medicine. It is impossible to seal them all. Therefore, special care should prevent the liquid from flowing to the stage and not touch the objective lens.

Do not disassemble the components of the biological microscope by yourself. Insert eyepiece or shackle cover on the lens barrel to prevent dust from entering the lens barrel’s upper part. Do not touch or wipe the lens surface with your fingers. If there is dust, gently brush it with a soft brush, and then wipe it with a soft clean cloth, or use lens wiping paper dipped in a little xylene or petroleum. But be careful not to streak the lens surface. If the lens is mildly mildewed and can’t be wiped off with a piece of paper, gently wipe it with a cotton swab dipped in 70% ethanol and 30% ethacridine mixture.

The biological microscope should not be exposed to direct sunlight, nor placed near the stove or heating, to avoid the degumming, deformation, or damage of lens and mechanical parts caused by excessive cold and hot changes.

The cleaning objective is limited to the outer surface. After drugs contaminate the object’s surface, wipe it with a little mirror cleaning liquid (do not use alcohol). If the back needs to be cleaned, wipe it with a soft brush or use a leather suction head to remove the dust.

After using the oil lens, the cedar oil on the lens of the biological microscope must be wiped clean (you can use the lens cleaning paper dipped in a little xylene to wipe, but the xylene can not penetrate the interior of the lens. Otherwise, the xylene will dissolve the adhesive between the lenses, and the lens will fall off).

Add mechanical part is inflexible, can use fine silk cloth dipped in xylene less Jun: wipe rust and greasy (do not use ethanol, because these solvents will corrode paint), and then a little liquid Shi Fu lubrication; twist too tight, do not force twist, lest damage.