Did you say horse or mouse?
I routinely process mouse tissue on a 9.5 hour program - perfect results every
time.
For heads I would do exactly as you are suggesting.
I've processed mouse uteri with full term pups in utero, transected prior to
processing - for about 15 hours after formalin fixation with consistently good
results.  Could you please describe this 53 hour schedule?  I hope at least 24
hours of it is fixation.

Jackie O'Connor HT(ASCP)
Abbott Laboratories
Jackie.O'Connor@abbott.com


                                                                                                                    
                    "Martin, Ronald"                                                                                
                                                                            
                                              cc:                                                                   
                    09/26/2002 07:40          Subject:     mouse processing issues                                  
                    AM                                                                                              
                                                                                                                    
                                                                                                                    




Fellow techs,
I have some processing issues with research mouse tissue I could use some
help with. A post doc and myself have a difference of opinions about some
procedures, three to be exact:
1)         Upon her request I processed several mouse pituitaries on a 53 (yes
53) hour tissue processing schedule. The tissue was friable and most of them
were embedded as fragments, with only a few remaining whole. I suggested a
shorter processing schedule such as their 15 hour cycle. Any suggestions or
feedback about this?
2)         Upon her request I processed whole mouse brains on a 53 hour
processing schedule. Before embedding she instructed me to cut the brain in
half from side to side. Regardless to say the tissue was friable and
fragmented severely. I suggested that the brain be processed on a shorter 15
hour processing schedule with the brain cut in half before processing. Any
suggestions or comments?
3)         Lastly, upon her request I processed whole mouse (pup) heads(with
skull intact) on a 15 hour processing schedule. She then requested that I
cut the heads in half from front to back (to see the pituitary). Upon
sectioning, most of the tissue wasn't properly processed. I could get some
sections but I didn't even attempt others. I had to reprocess the tissue
causing even more loss tissue. My suggestions were the following:
a)         bisect the skulls before processing for better fluid infiltration
and the brains won't fragment as badly as the will when they are cut post
processed. These could be processed on a 15 hour schedule or
b)         process the heads whole on a 53 hour schedule ( already tested with
good processing results) then bisect the heads. This would still cause some
fragmenting of the soft brain tissue. Any suggestions?

Thanks,
Ron Martin
Research Associate