[Histonet] fixation post-fixation, difference of order used

[ejschmid <@t> ucalgary.ca]

Hi,

I was wondering about the effects of using different fixatives in
 different orders. For example, some of our embryonic material (chick and
 mouse) is fixed initially with 4% PFA and subsequently is exposed to
 glutaraldehyde. Chick embryos subject to this are successfully labeled
 using IHC for anti-HH3.

However, our mouse tissues are fixed differently, being first exposed to
 4% PFA: 1% Glut solution (Which i think is called a modified Karnovsky's
 fix). These embryos perform poorly for IHC with anti-HH3.

Might it be the glutaraldehyde that is present in our primary fixative
 used to fix moue embryos? Might it be that the IHC works for chick because
 the glutaraldehyde is only used as a secondary fix after primary fixation
 in 4% PFA? Does the order of exposure matter?

thanks!

eric schmidt

University of Calgary
Medical Sciences