On Mon, 24 Apr 2000, Joyce Kotzuk wrote:

> Would it have to be a different enzymatic label for the second primary antibody, and if so, why? If acid washing undoes the antigen-antibody complex, does it take the secondary and link molecules off as well, leaving just the precipitated DAB or whatever? 

 The 2nd label could be the same enzyme, but demonstrated with a
 different method, and one that does not extract the end-product of
 the other enzymatic marker. 

 John A. Kiernan,
 Department of Anatomy & Cell Biology,
 The University of Western Ontario,
 LONDON,  Canada  N6A 5C1