Hello Fellow Histonetters,
I have a question I hope you can answer since it has caused me lots of grief.
Why will IHC slides not signal with DAB if they where first stained with Mayers Hematoxylin before the DAB was dropped on? On several occasions, this morning being the latest, Hematoxylin was mistakenly drop on the slides before the DAB. Part of  the controls had  DAB dropped on them and the rest where destained with 70% acid alcohol before the DAB was dropped. None of the control worked. WHY???  These are controls that  I know are staining nicely. As I said this is not the first time this has happened.  WE need help!!!!!
Thanks,
E.S. Shields
Baptist Hospital of E TN
Knoxville, TN