Here are 2 guesses (and they are just guesses).
  Bleach
  Acid    (acid elution is a standard blood banking technique to remove
bound antibodies, and if your antibodies go, the DAB goes with them)




>Hi Everyone,
>
>Can I just clarify that I know that the DAB precipitate is supposed to be
>permenant, and our lab has also been doing immunos for over 20 years.
>
>And this problem has only just occured. The staining was there before I put
>the slides into 70% alcohol and then the DAB staining had gone. Not even any
>specific staining was left.
>
>We did think of one possibility here that somethin could have contaminated
>the alcohol that would bleach the DAB??
>
>I have checked the pH and it is the same as before.
>
>Tammaryn
>
>National Institute of Medical Research,
>Department of Neurobiology,
>The Ridgeway,
>Mill Hill,
>London,
>England.
>FAX 0181 913 8523
>TEl 0181 959 3666 ext 2391
>
>


Phyllis Davie
Clinical Laboratory Supervisor
PhenoPath Laboratories
Seattle, WA
pdavie@phenopath.com
(206)374-9009  phone
(206)374-9009  fax