Stains in Microscopy

[Chris Yeates]

see: Lugol vs. Melzers solution - hemiamyloidity for a very useful contribution by Andreas G.

anyone seriously working on both the agarics and many of the ascomycete groups needs to have at least Lugol's Iodine - perhaps in two different strengths; for Lactarius and Russula - when dealing with all but the most obvious cases - yo need it to show the spore ornamentation; whether spores are amyloid or not is critical in separating genera like Mycena from look-alike genera such as Hemimycena - (OK some Mycenas show a negative Iodine reaction - but they're probably not really Mycena species - it's a polyphyletic genus and wild doubtless get carved up sometime soon - you're getting off the point ed.)

I have started to work on some resupinates I come across nowadays; I knew that people like Alick Henrici would always mount these in Congo Red, yet never bothered to get any and worked with water mounts - no wonder I gave up! Here are a couple of views of the septocystidia of Hyphoderma setigerum - the sort of "featureless" fungus I would never have considered collecting:
this cystidium is smooth with a distinctive clamp


these (more typical) cystidia are encrusted - again note the clamp on the left hand one:


those in water would be less than helpful - and I am using Congo Red in water (most people find it even more useful in ammonia)

Cotton Blue is invaluable when looking at the spore ornamentation in members of the Pezizales - Scutellinia (a much trickier genus than most newcomers seem to think) is a classic case in point; I find it exceptionally useful when the number and location of the pores on rust uredospores is critical

I'll get back to this thread with some useful links etc. Anyone else please feel free to chip in . . .

cheers

Chris

[Chris Yeates]

This is a useful link for beginners:
Guide to Chemicals for Fungal Microscopy

Chris

and see also: http://www.brunelmicroscopes.co.uk/solvents.html and http://www.brunelmicroscopes.co.uk/stains.html

I get no commission from Brunel Micro - honest!, but every time I have bought anything from them they have been very helpful (and in one case saved me quite a bit of money), so I am happy to recommend them

feel free to ask any questions about what you might need and for what purposes

C

[FungiJohn]

I can see the price of Lugol (£7.50 per 250ml) but when you click on the link to buy it's not listed

John

[Chris Yeates]

Another useful bit of info - gleaned from a recent article in Field Mycology

the presence or absence of chrysocystidia on the lamellar margin is important - particularly when dealing with the blue-green Stropharia species; it's also useful when looking at Panaeolus and some other genera.

"In order to observe these special cystidia they need to be treated either with ammonia, when the chrysocystidia will turn yellow, or with a basic food dye called Patent Blue V, when they will turn intensely blue. In my experience the reaction to ammonia can be rather slow and not very obvious, whereas when treated with Patent Blue V the reaction is immediate and unmistakable. Acquiring Patent Blue V might seem to be a problem since you need to contact specialist chemical suppliers but there is a useful alternative available. Thanks to research by Mark Gurney into food and other dyes I can report that standard disclosing tablets, sold at Boots chemists * to reveal plaque stains on teeth, contain this dye and stain chrysocystidia beautifully. Simply dissolve one tablet in 50 ml of water to make a dye solution. If present, the chrysocystidia will be revealed by a bright blue irregular mass inside the cell, easily visible even using low power objective lenses."

Here one can see unstained chrysocystidia - they're not always as easy to see:
Stropharia species with blue-green colouration

I know that Andreas has also mentioned "Patentblau" in a different post. So went out and got some today - can't wait to find my first Panaeolus -

cheers

Chris

* clearly there are other brands of disclosing tablets - I'm just forwarding the information in F.M., so I don't know if others have the same formulation

[BROCSMAN]

Funga Nordica refers to sulphidia in the Panaeolus/ini key, which appear to be chrysocystidia which do not stain yellow with ammonia. Do you know if they stain blue?

[flaxton]

I finally got the chance to try out the disclosing tablet on the cystidia of Stropharia cyanea (caerulea)



It works well and I will use this in future.

Mal

[Chris Yeates]

Originally Posted by flaxton

I finally got the chance to try out the disclosing tablet on the cystidia of Stropharia cyanea (caerulea)



It works well and I will use this in future.

Mal

It does work well - incidentally when he was over from NZ in spring Jerry Cooper stayed with me for a couple of days - he picked some up because (for some reason) you can't buy it in New Zealand

cheers

Chris

[Ditiola]

Hi
For a general purpose stain I use Erythrosin as it seems to give a good clear stain of the fungal tissues without staining too much of the surrounding xexexexe. It was Dave Minter who put me on to it many years ago as apparently he used it quite a lot. It is also available in most supermarkets as a red colourant for cake icing. It also cleans of slides more easily than congo red

I have been collecting information on stains over the years and have put my latest information sheet on a PDF file available to view at my 'Dropbox site' the link is below. I have not tried them all out it is just what I have accumulated from the literature. If there are any there that does not work or any useful ones that I have not listed please let me know.

Peter


http://dl.dropbox.com/u/25610275/Che...20Mycology.pdf

[Lancashire Lad]

Originally Posted by Ditiola

...I have been collecting information on stains over the years and have put my latest information sheet on a PDF file available to view at my 'Dropbox site' the link is below....

Hi Peter, I've just downloaded a copy of your document.

It contains some information that I'd been looking for, and much more that I wasn't even aware of.

Thanks very much for making it available.

Regards,
Mike.

[flaxton]

Great information thanks for sharing.
Mal