Date: 5 Mar 2001 12:55:14 -0600
From: conmac@cc.usu.edu
Subject: thanks re Methylene Blue eosinate

I have come to the conclusion that my old procedure is probably just a
Giemsa stain (we're staining for protozoan parasites), so that's what
I'm going to do.  To date, no one has been able to tell me just what
methylene blue eosinate is, so I'm assuming it is such an ancient dye
that it hasn't been produced in 90 years OR it has a completely
different name and isn't traced back to this older usage.  At any rate,
this has been a real puzzler and I thank you all for trying your
collective best to help me.

Connie M


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Connie, just saw your post today....The 7th edition of Biological Stains by
H.J.Conn(1961) The Williams & Wilkins Company talks about the methylene blue
eosinate (and others).

Inpart see below:
"The first worker to combine eosin and methylene blue was Romanovsky (1891).
He realized that a mixture of these two dyes had great selective properties
as a stain, and showed it to be excellent for blood, particularly in bring
out the malarial parasite..He also appreciated that it was more than a
mixture of the two dyes and that some new dye having the property of giving
the nuclei a red color was present.  It was some time later before the
nature of this new dye was known, although it was subsequently named azure I
or methylene azure; it's true chemistry has scarcely been understood until
recently(see pg.96).Methylene violet, and "methylene azure," which probably
was also present, had already been described by Bernthsen(1885). How these
new dyes were formed in the Romanovsky stain was not known; although
Romanovsky stated that different lots of methylene blue solution varied in
their ability to give a good blood stain, and that old solutions on which a
scrum had formed were best."

A great deal more is said, if you can find a copy it makes interesting
reading.....Azure I(Giemsa) and Azure II(Giemsa)

There seems to be several more "trade" names for the mixtures,trade names
for 'secret mixtures'.

Do find the book.

Hope this helps.

Susan