I have had good results from using Altmann's fixative for 2 hours on
yolk-rich material. Fixation renders good morphology but soft tissue. I also
wash in H2O before placing the tissue in 70% ethanol after fixation as when
using Bouin's. 

Post-fixation with a dichromate fixative, such as Smith's fixative, has also
been used for the demonstration of mitochondria and juxtaglomerular granules
and requires  washing in H2O after fixation to prevent the formation of an
insoluble Cr2O3 precipitate before storing or processing in 70% ethanol.

Altmann's fixative:

Chromium potassium sulfate                                    3.0 g
Formaldehyde (37-40%)                                          30.0 ml
Glacial acetic acid                                                    2.0
ml
DH2O
238.0 ml

Fix for 2 hours - do not fix longer or swelling will occur. 

Smith's fixative:

10% Formalin                                                        100 ml
Potassium dichromate                                              5.0 g
Glacial acetic acid                                                    2.5
ml

If you must use Smith's fixative, prepare it fresh, because potassium
dichromate reacts with formalin.


Eric C. Kellar
Histology/Immunohistochemistry
University of Pittsburgh Medical Center



	----------
	From:  David John Schmitz [SMTP:schmitzd@pilot.msu.edu]
	Sent:  Thursday, June 24, 1999 11:06 AM
	To:  histonet@Pathology.swmed.edu
	Subject:  axolotl (fwd)

	Forwarded message:
	From HistoNet@Pathology.swmed.edu Thu Jun 24 10:55:18 1999
	Date: Thu, 24 Jun 1999 10:04:48 -0400 (EDT)
	Message-Id: <199906241404.KAA19588@pilot008.cl.msu.edu>
	From: "David John Schmitz" <schmitzd@pilot.msu.edu>
	Subject: axolotl 
	To: histonet@Pathology.swmed.edu
	Content-Type: text/plain

	Hi  everyone,

	I am having a few problems with my histology.  I am trying to obtain
a stage
	series of axolotl embryos and I am having trouble because the have a
tremendous
	amount of fatty Yolk filled cells.  I have tried using bouinUs fix
and smithUs
	fix, and smithUs fix seems to work the best on the yolk. But, now I
have a
	number of embryos that have been fixed in buffered formalin, Can I
postfix them
	with SmithUs and have I work out OK?  If you have any other ideas of
dealing
	with the yolk problem, let me know .
	I am also having a problem orientating the very early stage embryos
and I heard
	that agarose can be use for this.  Dose anyone know how to use
agarose?
	 --




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