V Cleaning Optics Includes excerpt from “The Clean Microscope” ( > Support > Download Center

Basics Cover up your systems, so you don’t have to worry so much about cleaning – prevention is the best way. Don’t clean if it’s not necessary (no “routine cleanings”) If in doubt, ask a professional, don't experiment! Determine if you are actually dealing with “dirt” and not with optics issues. Rotate or move objectives, cameras*, specimen, condenser etc. to determine the location of dirt. Use the least aggressive cleaning method first. Find a comfortable and clean desk and sit down. Make sure there’s adequate lighting. Limit the amount of people present (people are the biggest source of contamination) * When the dirt stays in the same spot as you rotate the camera, it is located on the camera!

Cleaning Tools Magnifier (Loupe or Eyepiece) Puffer (Hand blower) Distilled Water (breath) Lens Cleaning Liquid Lens Paper Long, thin Wooden Sticks and High-Purity Cotton to produce hand-made cotton swabs –or– Commercial wooden Q-Tips (verify purity!)

Preparing your own Cotton Swabs

1. Blow loose dust particles away with a dust blower 2. Remove water soluble dirt with distilled water. If this is not working, use approved lens cleaner. Remove any remaining residue with a fresh cotton swab, but never while the surface is dry (breathe on surface to generate a film of moisture) 3. Oily dirt should be cleaned with a solvent such as an approved lens cleaner or mixture of 85% petroleum ether and 15% isopropanol. * 4. When using lens paper (or cotton swab), only swipe surface once and then use a fresh sheet. Paper and cotton are cheap by comparison! Never “rub” surface. 5. Blow remaining liquid on lens surface away from the center of optics until it has disappeared from the glass, then wipe it off the mount. Cleaning Procedure * Petroleum ether should be analytically pure and have the lowest possible boiling point. It also has to be fresh (hygroscopic!). Acetone, recommended exclusively for oil-contaminated cover slips or slides should also be analytically pure.

Words of Caution When Cleaning Microscope Optics ! 1. Do not use “canned air”. These convenient pressurized media may leave slight, but difficult to remove, residue. The pressure may also be strong enough to pick up dust from the surroundings and propel it at high speed at the surface (sandblasting!). 2. Never wipe lenses with dry swabs or tissue – this causes scratches! 3. Do not use abrasive materials e.g. leather wipes, dry linen cloths or polystyrene sticks as recommended by some manufacturers. 4. Do not apply any solvents before trying distilled water (a film of distilled water can be generated by breathing on the surface), except when grease is to be removed. 5. Do not use ethanol or acetone, especially not for the cleaning of older microscopes.

Words of Caution – continued 6. Do not use any disposable cotton swabs ( Q-Tip with plastic) in place of the described cotton 7. Never use metal rods in place of wooden (bamboo) sticks, as the lenses may become severely scratched. 8. Many dichromatic surfaces are too sensitive for even slight touches! A dust blower may be the only option. 9. Never use acids, ammonia, xylene to clean objective front lenses. 10. Never try to clean the internal optical surfaces, cameras or adaptor optics. 11. Never direct the dust blower towards internal optical surfaces, because dust may get lodged in areas which are not accessible any more.

Thank you. Enjoy your clean microscopes ! Rudi Rottenfusser Office: 508/ Cell: 508/ Microscopy Support:800/ Imaging Support:800/ Website: Educational Site: