Judy Trogadis wrote:
> 
> Thanks for the suggestions. I want to use fluorescence and confocal because > of the 3D information contained in thick sections ...

Microscopists have been getting 3D info from thick sections since 
the 1870s. Fluorescence microscopy dates from ? the early 1930s.
Immunofluorescence is almost exactly my age. Modern confocal 
techniques appeared in the early 1980s and flourished with the
affordability of computers. 

>                          ... rats are perfused with agarose which contains > fluorescent beads, the vessels and capillaries are outlined but we are 
> interested only in arteries. A suggestion of smooth muscle cell marker may
> work.

For distinguishing arteries from veins by virtue of their
anatomy,
if you're adamant about fluorescence microscopy, a general
fluorescent counterstain should be sufficient: any fluorescent
anionic dye, 
suitably diluted. The choice is determined by the colour you want
to see. 
             John Kiernan, London, Canada
-----------------------------------------------------
Old stuff follows.
> >>> "J. A. Kiernan"  11/28/01 12:39PM
> On Wed, 28 Nov 2001, Judy Trogadis wrote:
> 
> > We are interested in differentiating between arteries and
> >veins in the adult rat pulmonary vasculature. Are there specific
> > markers or antibodies we could use?
> 
> Why not use an ordinary connective tissue stain
> such as van Gieson's. Arteries have thicker walls,
> mostly muscle (yellow) and veins have thinner
> walls with relatively less muscle and more
> adventitial collagen (red).
> 
> > A fluorescent marker is required for the confocal
> > technique.
> 
> It would be, but with van Gieson you could do
> the job with an ordinary microscope - much
> cheaper and easier to use! For what it's worth
> the acid fuchsine component of van Gieson is
> fluorescent. The picric acid suppresses
> autofluorescence, and so does the Weigert's
> iron haematoxylin that's used to stain nuclei.
-- 
-------------------------
John A. Kiernan
Department of Anatomy and Cell Biology
The University of Western Ontario
London,   Canada   N6A 5C1
   kiernan@uwo.ca
   http://publish.uwo.ca/~jkiernan/