The magnification of ordinary biological microscope can reach 1000-1600 times. Generally, microorganisms such as fungi and yeasts are relatively large, and good results can be obtained with low-power objective lens and high-power objective lens. However, to see the morphology of stained bacteria and the morphological structure of eukaryotic cells, it is best to use an oil lens.
Oil lens is a kind of objective lens of microscope. The full name is oil stained objective lens. The medium of microscope objective lens includes air, water and oil. The latter two are used for high-resolution objective lens.
Master the correct use of oil mirror
1. When using the oil lens, first drop asphalt on the glass slide to increase the light entering the oil lens, enhance the brightness of the visual field, and make the object image clearer.
2. Put the microscope upright on the table, and do not bend the mirror arm to tilt the stage, so as to avoid the spillage of asphalt, affecting the observation and polluting the table.
3. Aiming
When natural light is used as the light source, plane reflector should be used; If artificial light is used, concave mirror shall be used.
First, open the aperture and rotate the reflector to concentrate the light on the light collector. You can move the light collector up and down and scale the aperture as needed to obtain the best brightness.
4. Focus adjustment:
① Place the specimen on the stage, fix it with the specimen pusher, and move the part to be examined under the objective lens. First find out the position of the specimen with a low power lens, then raise the lens barrel, drop a drop of lens oil on the specimen to be tested, and then change the oil lens for observation.
② Turn the coarse adjuster to slowly raise the stage (or gradually lower the lens barrel) until the oil lens is immersed in the oil. At this time, the eyes should be observed from the side to avoid crushing the specimen and damaging the lens.
③ Then move both eyes to the eyepiece, observe from the eyepiece, and slowly rotate the coarse adjuster (lower the stage or raise the lens barrel) in the opposite direction. When there is a blurred object image, change to the fine adjuster, and rotate until the object image is clear.
④ After observation, the lens barrel should be raised first, and the oil lens should be twisted to one side before taking down the specimen. After the oil lens is used, the oil on the lens shall be wiped off immediately with the lens wiping paper. If the lens oil is dry on the lens, the lens can be wiped with a little xylene dipped in the lens wiping paper, and then the residual xylene can be wiped off with the dry lens paper to prevent the xylene from penetrating and dissolving the gum used to fix the lens, causing the lens to shift or fall off.