Carnoy's will work for mast cells, both connective tissue and mucosal mast
cells.   There is a publication (at home, not work, can't pull it) written back
in the 80's by Patricia Crowle on staining these two populations of mast cells
CTMC (connective tissue mast cells) and MMC (mucosal mast cells).  They differ
biochemically, hence differences in how they stain.  

NBF will also works with connective tissue mast cells, not very well for
mucosal population.  

We preferred the Churukian Schenk (sp?) toluidine blue method for CTMC.  
Stain worked on decalcified bone too! No background staining and uses a
permangante oxidation step.  It takes only an hour or less to do the stain,
with beautiful results, mast cells standing out as individuals without
messy blue everywhere.  I highly recommend this simple stain for anyone doing 
routine mast cell staining in their lab.   

Positive control for connective tissue mast cells was skin,  had a 
mastocytoma  (overkill, with lots of funky cells) also.  For mucosal mast
cells, a good control was parasite infected mouse intestine, and used astra
blue staining, highly acidified, with light eosin counterstain, these tissues
were always fixed in Carnoys without chloroform, safer and still worked.  

Enerbeck did huge studies on mast cell staining, before 80's,  and have his
references for differences in mast cells,  just can't get to them this week but
if you think you need them, later.   

Gayle Callis