I have a NovaRed from Vector, just starting to use it.  Zymed must have 
a new substrate/chromogen also.  The Vector product is for HRP systems,
5 times more sensitive than AEC, equivalent to DAB, a brick red, and
can be dehydrated through alcohols, clearants and permanent mounting media.
What a joy! to be able to handle a red end product like DAB!
  
I found that with one antibody I was using, I will have to do 
further dilutions on the primary.  And this will probably be the case with
other antibodies as well.  The color developed FAST, maybe too much so.  

Gayle Callis