We did frozen sections on blood clots to stain for fat embolism per a
publication for this technic. 

Draw a tube of blood, 5 - 6 mls, allow to clot approx 1 hour or longer
until very firm, less blood could be drawn. Remove clot from tube (slides
out) cut into 5 - 6 samples, and mount in OCT, cut frozen sections, fix FS
immediately with NBF, than did an OIL RED O stain counterstained with
hematoxylin and blued.   We had several traumtic injury patients with
severely broken bones and  breathing problems, fat embolism was suspected.
Yes, fat droplets from bone marrow were present in the blood. The longer
you let the clot sit, the firmer it became. One could fix the clot in the
tube if they wished, I would change the formalin a few times.  

You can cut the clot at a slightly warmer temp in cryostat if it tends to
shatter, -16C or so. 

   
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