We have been experiencing major processing problems. (any of these can occur or all at the same time:  extremely dry, extremely brittle, extremely hard, color changes - turns dark after processing, shrinkage, almost cooked look.)

Also its not every time we process tissue.
I have changed processing times.
Changed from reagent alcohol to isopropyl alcohol.  (We use Xylene for clearing)
Checked the temperature of each solution during processing.  The process chamber is filled and just prior to draining.

In the past, Sprague Dawley rats were mostly used.  Now we are receiving many strains and altered rats.
Our main problem is with bisected kidneys.
Rats in general are very lean.
Could it be the variation of the rats?  The strain difference?  The age of the rat?
Is Isopropyl Alcohol the best for animal tissue?

The rat hearts, aorta's and brain from the same animal process fine.
Mouse tissue received has also processed fine.

Has anyone else noticed this difference?

I'd like to thank all of you out there that have already shared their knowledge with me.  Any more tips, suggestions would be greatly appreciated.

Thank you,
Carol Ann Bobrowitz
Physiology & BRI Histology Core Lab
Department of Physiology
Medical College of Wisconsin
Milwaukee, Wisconsin
cbobrowi@mcw.edu
(414) 456-8179