Jason, 

I am gathering that you are trying to maintain RNA for ISH purposes, correct? 

If so, long term storage of fresh tissue frozen sections will probably mean
RNA degrades (RNAse problem). If you wrap each slide in foil, then the foil
must be RNAse free. I have a colleague who does this and also taught by a
lady from Iowa for ISH/PCR work.    

If doing LCM for ISH or just ISH directly on a frozen section, the section
should be collected into either a box or metal slide tray cleaned with 70%
alcohol.  These are sitting on dry ice. Slides are never allowed to sit
outside cryostat or off dry ice during sectioning.   For storage, she
stores FS in a slide box with bag of 16 mesh silica gel, put into zip lock
baggie, and stored at -80C.  This minimizes the possibility of degradation
although she has experienced loss of RNA and prefers to do ISH after
sectioning/fixation.   

  
Gayle Callis
MT,HT,HTL(ASCP)
Research Histopathology Supervisor
Veterinary Molecular Biology - Marsh Lab
Montana State University - Bozeman
S. 19th and Lincoln St
Bozeman MT 59717-3610

406 994-6367 (lab with voice mail)
406 994-4303 (FAX)

email: gcallis@montana.edu