Amanita phalloides poisoning diagnosis

Heine J. Deelstra heine at
Mon Sep 10 01:40:28 EST 2001

"Constantine P. SEMENCHUK" wrote:

> Because we have not access to some reliable methods of laboratory
> confirmation of the Amanita phalloides poisoning we have to use
> determination of amatoxins by Meixner test. I have not detailed
> description of the test -- only brief one. Therefore I do not know how
> to perform the test in the case of the poisoning. For example, I do
> not know in which proportion and for which purposes one should dilute
> gastric contest with methanol. I will be very grateful to you if you
> will help me with solving some question concerning Amanita phalloides
> poisoning, i.e. microphotography of spores of Amanita phalloides
> (examination of gastric contest for the spores is only method of
> verification of the poisoning available in our hospital.

Hello Constantine,

The Meixner test is only valid on the mushroom itself and not on the
stomach contents of victims.
Spores can be examined under a normal light microscope and stained with
Melzer solution, which turns the spores of amatoxin containing mushrooms

See also
for Lab studies.

is also useful.
Melzer reagent:
20 mL water, 1.5 g potassium iodide, 0.5 g iodine, and 20 g chloral
hydrate. One drop mixed with some spores and then viewed under a
microscope can determine if the mushroom is an amatoxin-containing
mushroom such as the cyclopeptide-type (Amanita phalloides) mushroom by
the bluish black amyloid surrounding the spores.


Heine Deelstra

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