Journal of Histochemistry and
Histochemical Society, Inc.
Letter to the Editor
43. NO. 9,
Printed in U.S.A.
Contrast Staining with
Reduced Osmium Complexes
Recently I read a Technical Note in the
Journal of Histocbemistv and
entitled: “Improved method for post-embedding cyto-
chemistry using reduced osmium and LR White Resin,” by Hideaki Tamaki
and Shohei Yamashina.
On the one hand, I was glad to see the revival of the use of ferrocyanide
an additive to Os04 post-fixation in LR White resin procedures. On the
other hand, I was disappointed when I noticed that (in a historical sense)
the authors were referring to Karnovsky’s short
to my more informative
in which the use of reduced
mium was introduced, or to later works by White et al.
This aspect alone would not justdy a letter to the editor. However, in the
from the bottom) incorrect statements are
present that might have escaped the referee’s attention: “The mechanism
of fixation by
is not fully understood. Its powerful oxidizing effect
may be responsible for the fixation of macromolecules (reference to Pearse).
We speculate that the effects of osmic acid [sic!] on decreasing cytochemi-
cal reactivity are minimized by reduction with potassium ferrocyanide. There-
fore, reactivity with moderately adequate fine structure is retained.” This
is followed by two references
about the use of reduced
mium for improving membrane contrast.
I will not exclude the possibility that the first line of the quotation may
have been truncated in the process of typing and printing, and that it orig-
inally might have read, “is not fully understood by
or, “and is not available
to us,” because original papers of early dates are parked along the electronic
highway in library search systems,
for example, in our library system,
in which papers dated earlier than
are no longer accessible electroni-
cally and papers one decade before that point require special hand aching.
To counteract the impact of this discussion and to contribute some in-
formation in a positive way, I give below a short summary of “stale” infor-
mation about this aspect of reduced osmium tetroxide in papers from our
excluding, in an unfriendly way, those
from other authors active in that period:
1. After the initial introduction in
the selectivity of o~(v1II)o~
plus complex cyanides such
glycogen and membranes was given and illustrated in