I'm a Newbie - Need help cleaning objective lens.

[Jonnyvine]

Hello. I’m new to microscopy and I just bought a cheap second hand Bresser Biolux on eBay. I did some checks and everything seems alright apart from the 40x objective lens which has a dull colour, possibly oily or dirty. I need expert advice on cleaning the objective lens as I’m completely clueless. I saw a video on how to clean it but I urgently need advice on which chemicals to actually use. I need a solution that is fast & cheap. Can I use diluted water & alcohol? Or can I just use water for now to temporarily clean the lens? Your replies are much appreciated.

[Hobbyst46]

The best way to closely inspect a dirty objective is through an inverted eyepiece, which acts as an efficient magnifier. Use side-lighting and you will see the soiling or staining or other problem on the glass surface.
Start by exhaling on the objective to cover it with a visible layer of moisture. Then wipe it just once with a fresh piece of lens tissue or, better, a KimWipe tissue. Fold the paper in two, exhale on the glass and wipe again. A very soft silk-like piece of cloth, supplied by optometricians for eye-glass cleaning, can also be used but I prefer KimWipes.

If the problem stays, let the objective dry, then use a Q-tip immersed in rubbing alcocol (isopropanol) or light petroleum (e.g. heptane, octane) to wipe the lens. Use the minimum amount of liquid!

In very difficult cased one may use xylene - but the smallest amounts of it.
A very dilute solution of a mild liquid soap is permissible - again, the least amount. Apply with a Q-tip, then rinse with distilled water.

Never ever use any harsh liquid like bleach, caustic soda, acid or drain cleaners.

Never use acetone or chloroform.
I think that ethanol should be avoided as well. Although it is less powerful than acetone.

[MicroBob]

There is nothing much to add to Hobbsyst46s description. Generally one major reason for scratched lenses is improper cleaning. Since there might be abrasive dust in the goo on the lens you use every part of you tissue only once. The front lens is cemented in. When you remove the cement you have a paper weight. My paper weight is an exclusive one: A Leitz Planapo 100!

Bob

[75RR]

Have a look at the linked pdf: "The Clean Microscope" by Zeiss

Can't really go wrong if you follow its recommendations.

viewtopic.php?f=15&t=1428

[MichaelG.]

A very dilute solution of a mild liquid soap is permissible - again, the least amount. Apply with a Q-tip, then rinse with distilled water.

Jonnyvine: The advice given thus far is excellent, so I will just add that a dilute solution of Alberto Balsam 'Tea Tree Tingle' shampoo makes an unlikely but amazingly effective water based lens cleaner! ... It is available very cheaply at UK Supermarkets.

I have no idea which of the ingredients does the trick !!

MichaelG.

[Jonnyvine]

Thanks [75RR] and everyone else, your advice was very helpful.

[Nance]

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[Nance]

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