Confocal Microscopy List

Re: Cleaning lens.

Posted by Dan Focht on
URL: http://confocal-microscopy-list.275.s1.nabble.com/Cleaning-lens-tp2556737p2572081.html

Confocs

While this thread is still active I'll take this opportunity to remind you that after you clean an optic with an oil solvent make sure that you also clean it with a water based cleaner then distilled water. Often times the petroleum solvent will not remove sugars and salts that may have been left behind from media or fingers. The oil covers it up and you don't notice it but the image suffers.

Also make sure that all oil is removed from an objective especially after it has sat around for a while before applying more oil. If a thin film of oil is left on the objective overnight or over a weekend the oxidation changes the RI and viscosity of the oil leaving an irregular RI surface. If new oil is then added to this irregular surface the image is diminished. In my former life, when I serviced scopes, I often had customers that religiously blotted their immersion objectives with lens paper at the end of the day leaving behind a thin oil smear layer. They then added more oil to view a slide the following day. After a proper cleaning of the lens with petroleum solvent then water based cleaner and distilled water they were amazed at the improvement.

I believe the distilled water is a necessity. Take whatever glass cleaner you choose and let it evaporate on a mirror surface. It will leave a residue. The distilled water is necessary to remove this residue and leave a pure glass to air or glass to oil interface.

Dan

From: Confocal Microscopy List [mailto:[hidden email]] On Behalf Of Ian Montgomery
Sent: 30 March 2009 12:28
To: [hidden email]
Subject: Cleaning lens.

            In one of our teaching labs many years ago a student complained they were having a problem with the x100 OI objective and sure enough the image was lousy. I cleaned the objective and slide then re-applied a spot of oil and still the image was lousy. I then asked the student how exactly they had set up the microscope. Shock horror, my world collapsed. They had unscrewed the objective, filled it with oil, screwed it back on then put a drop on the slide. After weeks of trying to clean the objective it went into the trash as beyond economic repair.
            Cleaning objectives, I use the fluid recommended by the local Zeiss engineer, 90% methylated spirit and 10% isopropanol.
Ian.

Dr. Ian Montgomery,
Histotechnology,
I.B.L.S. Support Unit,
Thomson Building,
University of Glasgow,
Glasgow,
G12 8QQ.

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Dan Focht

Bioptechs

724-282-7145