MicrobeHunter.com Microscopy Forum

Like many amateur microscopists, I have felt my way, and pursued this hobby alone. Thus, I'm often not aware of "best practices" according to others.

I prepare almost entirely wet mounts for Protista. I use 0.17 mm coverslips, throw away the old ones, and grab a new one. Ditto, slides. I have lots of boxes and just grab a clean one.

But suppose I wanted to limit myself to one tray of slides and a container of coverslips?

What would be best practices for cleaning and re-using?

My guess would be: Rinse in distilled water, dry on filter paper, use forceps to return cover slips.

And is cleaning and re-using cover slips even worth the trouble?

What are "best practices"?

I use 0.17 mm coverslips, throw away the old ones, and grab a new one.

Do you measure them with a micrometer?
I find that there are not too many actual 0.17mm cover slips in a box - seems very wasteful to throw them away after a single use. I wait until they are well scratched.
Slides will last for ever or until you drop them - whichever comes first.

I add a drop or two of Isopropyl alcohol to them before cleaning under the tap using washing up liquid.
Dry with tissue paper - polish with kimtech.
Hold with fingers on edges.

I often buy Chinese cover slips, not because they are good quality but they are cheap (1-2 USD per 100) and more importantly - they are in stock. For Quality coverslips I have to wait many weeks.

Those cheap coverslips are initially not clean. Rather, they are stained with some white powder or some other stuff. Rubbing them with a dry tissue or with an alcohol-wetted tissue is futile. But they are nicely cleaned with soapy water - any dish cleaner will do. Then rinsing with water and polishing with lens tissue. I often use them once. I do recycle slides many times.

75RR wrote:

I use 0.17 mm coverslips, throw away the old ones, and grab a new one.

Do you measure them with a micrometer?
I find that there are not too many actual 0.17mm cover slips in a box - seems very wasteful to throw them away after a single use. I wait until they are well scratched.
Slides will last for ever or until you drop them - whichever comes first.

I add a drop or two of Isopropyl alcohol to them before cleaning under the tap using washing up liquid.
Dry with tissue paper - polish with kimtech.
Hold with fingers on edges.

The use of a micrometer for this purpose is new to me. Is there a reason why I should not trust the manufacturer's claim of 0.17 mm? These particular coverslips are different from my others; they are glasslike. And buy a micrometer only for this purpose? Hmm, I think I'll combine my idea with yours, add isopropyl alcohol to distilled water and use as a cleaning/rinsing bath. I am reluctant to use any kind of washing up liquid on wet mounts given that there is a metabolically sensitive food chain (bacteria and protista).What is Kimtech, please?

Cover slips come in different sizes and different thicknesses.

Sizes can range from 10x10mm to 20x40mm or more.
Cover Slip thicknesses always lie within a range.
Each range is numbered: i.e. #1 Cover Slip = 0.13-0.16mm, # 1.5 Cover Slip = 0.16-0.19mm (These variations are part of the production process)
Thicknesses can often extend outside the declared range.
One should only buy Cover Slips that are made of glass.

Keeping strictly to the stated 0.17mm written on the objective is really only of importance when using dry objectives of 0.65NA (Numerical Aperture) or over.
Objectives with a NA < 0.40 are much more forgiving of cover slip thickness.

Incorrect cover slip thickness used with high NA objectives can undo the advantages that a good quality (and therefore expensive) objective can provide.

https://www.nikon.com/products/microsco ... /index.htm

https://www.amazon.com/Kimtech-Science- ... ds=kimtech

I once bought chinese round cover slips from ebay - they were from 0,13 to 0,25mm
Micrometers were much in use as long as manual machining was the norm. Today the machines have measuring systems and the tools are pre-measured before use. As long as you don't brutalize it a micrometer is very long lasting an dependable. So it is quite easy to buy a cheap 0-25mm micrometer for a couple of €. If you only buy dependable quality of cover slips you don't need a micrometer, but then you should discard all cover slips that come into your property from unknown sources.

Some people are quite successful with cleaning slides in the dish washer. When you take half the base of a 100x slide box and cut big holes in the bottom with a hole saw, you can put it in the top drawer of a dish washer. I myself was not fully successful with this method.

On my desk I have two containers: One for glass rubbish, one for glass to be cleaned.

I clean my slides but throw away all cover glass after use. I have a box with glass to throw away and a box with glass to be cleaned. I never use cleaning fluid. Just rinse under tap water and wipe it off with a fiber cloth or my T-shirt. I only try to use high quality glass. All on ebay in bulk packages. Last years I have exclusively used glass from Fisher Scientific ("Fisherbrand"). I never pre-clean the cover glasses. They are clean enough out of the box. Never had an issue with huge variation in cover glass thickness, but my two favourite high magnification objectives both have correction rings to play with so I may have been compensating without knowing.

Great question, 'Linux...'! As part of wetmount slide preps...is sensible shutdown after a wetmount slide is used. I reuse the slides till scratched too much...I always dispose of the cover-slips.

Every observing session I have my lid covered slide box..it has a variety of quality slides...some single 'depression well' slides, some double 'depression well' slides..and a lot of high quality slides.


I have a variety of large rectangular cover slips, each in their boxes...these are in a bench draw..not at the bench surface as is the glass slide box. These I mainly use: #1 thickness slips...I do have #1.5 cover slips as well. The key point is: use large rectangle cover slips...and not simple 'squares', or simple 'round' slips...I do have the 'squares' and the 'rounds'..but these are in a bench drawn which holds othe boxes of slides and all sorts of kit.

Large rectangle slips offer a lot of area to observe with oil-bridged objectives/ or with water-bridged objectives...far from the wetmount slip/slide border areas. Less chance of 'gunking your immersion objective lens-face with sample fluids...by avoiding the cover slip border areas.

At each session start..a 5-7 oz. paper cup filled with tapwater..we have our own well water...is used to flush pipets before and between use...to feed slides as the water under the slips dry down...and at shut down...to flush cover-slip off the slide...into trash bag ? 33 gallon plastic trash bag in it's holder bin?...right afjacent to my chair at the microscope bench.

Immediate flushing with copious water of the reused glass slide..followed by ethanol, or isopropyl alcohol dropps and paper wipe down of glass slides...keeps all ready for the next wetmount..which might be in same observing session..or one session may be one wet mount slide...repeatedly 'fed waters' at edge of the cover-slip...possible for hours. If a slide has super keen organisms or structures..if your session is interrupted by dinner, or chores demanding attention ( a bat flying in the house perhaps?!)...a simple wet-box can hold a wetmount slide for hours , to overhight...have a simple 'wet mount slide box in a draw with your microscopy kit.

A camera type 'air-bulb' air blaster is puffed on glass slides if need be.. before the slide is used. This 'air bulb' is essentianl to optics at start of sessions, when optics are switched during sessions, and so like the slide box, like the alcohol dropping bottle..the air bulb is on the bench surface for it's almost obsessive/ compulsive use.

The pipett is often flushed from the water cup..the flushings squirted back into the sample jar, at end of pipet use..it is repeatedly water flushed...then lastly the alcohol is dribbled down into the pipet from it's bulb end ( the bulb remved for this !). The drizzle of alcohol flush goes into that nearby trash bag.

At end of session that tapwater cup is dumped into the culture jar...or my indoor plants...and the cup disposed into the near to bench trash-bag.

I high school ( a lomg time ago, gulp!, I washed and reused the collection of 'simple square cover slips' my highschool biology teachers gave me for home useage...thank you Br, Tim Ford/ thank you Mr. Nick Colleto!).

So nest your slide and coverslip procedures..into the context of a comfortable bench, proper chair, within reach trash bag...concepts of quality slides...large rectangular slips for optimal observing area away from the coverslip border areas...idea of water flush/ alcohol dropping bottle/ paper towel snips for shut down wipes of the slides.

If you can find the thread..in this great microscopy forum is a thread which: 'shows a variety of our forum member home microscopy benches'..please visit that thread...perhaps post images of your bench into the thread( hint, hint).

Great posting you share here, thank you! Charlie Guevara, finger lakes/ US.