Beverly,
We use Dako's SMA 1A4 routinely in our lab.  For formalin fixed and paraffin
embedded human and rat tissue, we use a dilution of 1:000 for 1/2 hour RT,
after Microwave A.R. (2 x 3 min high, followed by 10 min rest in hot citrate
buffer).  We follow with Vector's Rat Absorbed, Horse anti Mouse
Biotinylated secondary (30' RT), Vector's ABC Elite(30' RT) and Biomeda's
DAB (2x5')and a light hemotoxylin.  For mouse tissue we use Dako's
SMA-EPOS system (neat-1:15 depending on the tissue) - this works
beautifully!!  Hope this helps!
Chris Rogahn
crogahn@prius.jnj.com
(215) 628-7975