Staining and Entolomas

[ppenna]

Hello
I am having trouble seeing if the pigmentation in Entolomas is encrusting or intracellular and wondered if there were a stain which would make this clearer. I usually use Congo Red but this isn't particularly helpful. can anyone help?

Thanks
Pauline

[Chris Johnson]

Hi Pauline

I don't find stains too helpful in looking for encrustation and just use water. You can always add a little Congo Red later to look at the hyphae in more detail.

It will be interesting to hear what other members do.

Chris

[Chris Johnson]

Hi Pauline

So as not to mislead you, I have attached a couple of Entoloma images to show my finished images are always stained and the crustation can still be seen.

Having viewed them in water I leach a VERY weak solution of Congo Red though the preparation; once the hyphae have absorbed what they require, I flush the surplus stain out with more water. As you can see, the crustation is still visible. The preparations are from the pileipellis.

The Entoloma xanthochroum image is an early one when the microscope set-up had a severe yellow colour cast - all part of the learning process.

Hope this helps.

Chris

[Leif Goodwin]

Hello Pauline

Machiel Noordeloos in Fungi Europaei 5 recommends a saturated sugar or salt solution for fresh material, or 10% KOH for dried material. I can't say I have tried the first options. Clearly Chris's method works too. Staining then washing as Chris describes helps contrast, although I usually choose the easiest approach first.

Leif

[ppenna]

Thanks for that Chris and Leif, I've probably gone a bit heavy on the congo red, masking the intracellular brown pigment. We have had a lot of grassland Entolomas this year, I find them a real challenge.

[Chris Johnson]

I think we all find Entolomas a challenge.

Where about in the country are you?

Chris

[ppenna]

Hello Chris

I live in west Cornwall, a bit out on a limb really!

Thanks for your assistance.

Pauline