Luis:  Glen is right, smooth muscle actin will delineate the muscle coats of
venules and arterioles and larger vessels. To include capillaries, I'd use
CD34, it is very resistent to formalin fixation and requires no antigen
retrieval whatsoever. It also stains interstitial fibroblasts in most
collagenous connective tissue but this shouldn't be problematic since the
vessel morphology is so distinct.

Mary Ann- the bluing solution (not clarifier, which is just an acid alcohol)
is an aqueous lithium carbonate solution, not alcoholic.

Jeff Silverman HT HTL QIHC (ASCP)
Southside Hospital
Bay Shore NY USA