Notes on the Operation of Biological Microscopes
① Handle the microscope gently. Avoid shock and rough force, which may deflect the optical axis and impair observation, and the optical glass is also prone to damage. Do not place the microscope at the edge of the workbench; position it 10 cm away from the edge to prevent it from being knocked off.
② The threaded mount of the objective lens is easily damaged, so take extra care when installing objectives. Rotate it slightly counterclockwise first until the convex and concave surfaces engage, then turn clockwise. Do not over-tighten; screw it lightly to the stop and give it only a slight extra twist.
③ Specimen inspection must follow the operating procedure strictly. Start observation with the low‑power objective, and switch to high‑power or oil immersion objectives only after the specimen is clearly focused.
④ For the oil immersion objective, add immersion oil onto the coverslip before use. Immediately wipe oil residue from the lens and coverslip after use; dried oil is difficult to remove and may damage the lens and specimen. Use only a minimal amount of xylene. Excessive xylene can dissolve the cement inside the objective, causing lens tilt or detachment, and may shift or even dissolve the coverslip together with the specimen.
⑤ Carry the microscope by gripping the arm with your right hand and supporting the base with your left hand. Never lift it with one hand, to avoid parts falling off or collision. Do not touch optical glass surfaces with fingers. If cleaning is required, follow the specified procedure for optical components.
⑥ Center the slide specimen over the aperture of the condenser. Do not mount slides backwards, to avoid crushing the coverslip or striking the objective. Coverslips and slides must have suitable thickness: standard coverslip thickness is 0.17 ± 0.02 mm, and standard slide thickness is 1.1 ± 0.04 mm. Incorrect thickness degrades imaging and observation.
⑦ Do not remove the eyepiece casually, to prevent dust from falling onto the objective. Do not disassemble any components arbitrarily to avoid damage.
⑧ Develop the habit of keeping both eyes open during observation: use the left eye to view the field of view and the right eye for drawing.
⑨ Restore the microscope before storing it in its case after use: remove the specimen slide, rotate the nosepiece to move objectives away from the condenser aperture, lower the stage, lay the mirror flat, lower the condenser (without touching the mirror), close the diaphragm, reset the slide holder, cover with silk cloth and outer dust cover, then place it in the cabinet. Fill out the usage log afterward. (Note: The mirror is normally stored vertically. It is laid flat here because if the condenser is not raised properly, the lowered stage may collide with the diaphragm.)
