[Histonet] Mouse pups and processing

[Pamela Marcum]

I have been struggling with this for a while and need some help.  We 
currently have a project with 0 day mouse pups that are allowed to be 
born normally and then sacrificed with CO2.  We had several groups 
earlier that were sacrificed a different way and they processed and 
sectioned beautifully.

These don't seem to fix well, dehydrate, clear or infiltrate worth a 
darn.  Since this is my first time using CO2 for sacrifice I need to 
find out if it causes a problem or if I am just losing it.  I have 
not ever had this problem before and even re-processing does not 
help.  I know they are not infiltrating as they are floating in 
paraffin at the end if I remove them from the processor to a vat of 
paraffin.  They will not sink.  The pups are 1.2 to 1.3 grams each.

If you can suggest a better way to sacrifice them please let me 
know.  Killing the mother and perfusing her is not an option as these 
are not our mice.  They are being given as favor so I am limited to 
some extent.

This was an overnight process with slightly altered alcohols to 45 
minutes each, 1 xylene at 30 minutes and 2 Shandon Xylene Substitues 
at 10 hour each to 4 paraffins at 45 X2 and 1 hour X2.

Best Regards,

Pamela A Marcum
Manager, Histology Special Procedures
University of Pennsylvania
School of Veterinary Medicine
R.S. Reynolds Jr.  CORL
New Bolton Center
382 West Street Road
Kennett Square, PA 19348

Phone - 610-925-6278
Fax     - 610-925-8120
E-mail - pmarcum <@t> vet.upenn.edu