How to use the 100 oil lens of biological microscope correctly
(1) First, use a low magnification objective lens to locate the specimen, then switch to a high magnification objective lens for observation. Move the specimen to the center of the field of view, place the aperture at the maximum position, lift the lens barrel by about 1.5 centimeters (or lower the stage by 1.5 centimeters), and rotate the objective lens away from the optical axis.
(2) Remove the specimen slide, drop 1-2 drops of cedarwood oil onto the lens plane at the top of the spotlight, and then place the specimen slide back in place, ensuring that the underside of the glass slide is in close contact with the cedarwood oil to prevent gas saturation in the oil. But in normal operations, this step can be omitted.
(3) Drop 1 drop of asphalt on the cover glass or the area to be observed on the smear specimen. Shift the oil mirror to the optical axis and carefully adjust the coarse focusing screw to slowly lower the lens. Carefully observe the distance between the front end of the oil mirror and the specimen. Stop the descent when the front end of the oil mirror starts to touch the oil droplet. This operation process requires great caution to prevent accidents such as the oil lens crushing the specimen and damaging the oil lens.
(4) Observe from the eyepiece with your left eye, and adjust the fine focus screw with your right hand to gradually focus the lens to the correct working distance until you can see the specimen image clearly. Please note: Do not make mistakes in coarse and fine adjustment of the focus screw. The cover glass should be thin. If it is too thick, it cannot be focused, otherwise it may crush the specimen and damage the lens.
(5) Adjust the aperture size to match the numerical aperture of the spotlight with the oil mirror to obtain a clear image.
(6) After observation, promptly carry out cleaning work. First, raise the oil mirror to a distance of 1.5 centimeters from the specimen, rotate the oil mirror away from the optical axis, gently suck off the oil on the oil lens with dry wiping paper, then wipe twice with xylene soaked wiping paper, and finally wipe 2-3 times with clean wiping paper. Clean the oil droplets on the spotlight using the same method. The cedarwood oil on the specimen can be wiped clean using the paper pulling method, which involves covering the oil droplets on the specimen with a small piece of lens wiping paper and then adding some xylene onto the paper. While the paper is still wet, pull it outwards for 3 to 4 consecutive times to clean the smear without damaging the specimen.,,
