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Using a Microscope: Working with Dried Material

by Michael Kuo

Believe it or not, it is often easier to section a dried mushroom cap than a fresh one--and if you collect as many mushrooms as I do, you have no choice but to study your mushrooms after drying them. See Preserving Specimens for the basics of preserving your mushroom collections for later study.

Break off a small piece of your dried specimen's cap, and let it soak in 90% alcohol for a few minutes. Then transfer your specimen to a tap-water dish, and let it soak until it is soft (usually a few minutes). Don't be surprised if your mushroom piece starts spinning around once it makes contact with the water; I'm not sure exactly what's going on, but it has something to do with the alcohol-then-water factor.

Blot the piece of the cap well with a paper towel, then roll it up tightly, so that the gills run lengthwise in your roll-up. With a very sharp razor blade, begin slicing cross-sections of the roll-up, until you have managed to slice a very thin section. Transfer it to your slide, and add your mounting medium (probably 2% KOH, with a stain like phloxine). Your section should begin to uncurl itself; help it along with a toothpick, spreading it out so that the gill sections are well separated. Your section should look more or less like the "Roman aqueduct" one creates with fresh material. You will probably need to trim away parts of your section with the razor blade, to avoid having too much material on the slide.

Rehydrating and sectioning dried material

The mushroom under study in the illustrations is Pluteus petasatus, which has gorgeous, antlered cystidia covering its gills:

Pluteus petasatus

Rehydration of dried Ascomycetes should follow the same method--but I have found, in working with Morels, that the sections I slice from the spore-bearing surface are so small and thin that they are better rehydrated on the slide itself, in the mounting medium.

A special note for those who are studying dried boletes is in order, since a cross section of the tubes is much more difficult to slice after the cap has been rehydrated. I simply start slicing paper-thin shavings from the dried pore surface, and allow the section to rehydrate on the slide in the mounting medium.



Cite this page as:

Kuo, M. (2006, February). Using a microscope: Working with dried material. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/microscope_dried.html

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