Dear Histonetters,
	An investigator came to me today with a strange request.  She is
growing small pieces of mouse aortas in a collagen and fibrin gel.  She
would like to be able to stain the aorta and the cells growing from it,
without staining the gel.  She wants to perform the stain on the whole 1-2
mm thick plug without sectioning it in order to try and count the number of
cells that have grown off of the aorta.  I have suggested that processing
into paraffin may give her more success, but she is really looking for a
quick and dirty instant answer.  (Doesn't this sound familiar?)   
	Since, ideally, the method chosen should be relatively simple, I am
going to first try a nuclear fast red, or maybe a hematoxylin (without
eosin), or even a DAPI stain.  My thinking is to stain the nuclei, and avoid
cytoplasm (I think that in these cells the cytoplasm and aorta itself will
have collagen in them).  
	My second idea is to try a fluorescently labeled S-100 antibody,
(using the most abbreviated protocol I can find!) to label the cells only.

	But I am having a lot of trouble finding any other methods.  Most
books are organized by what you want to stain, not by what you are trying to
avoid staining!   If anyone has had any experience with this sort of
staining, or has any ideas, I would appreciate hearing from you!  
Thanks,
Jennifer Johnson
jennifer.johnson@genzyme.com