Garry;

The only  reason I can see to use two enzymatic antigen retrievals is that the
trypsin antigen retrieval in the protocol is not sufficient enough.  I actually
use DAKO's  vonWillebrand Factor VIII at a dilution of 1:4000 using DAKO
trypsin  for 30 minutes in 37C water bath for my antigen retrieval. Let me know
if you want me to send you my entire protocol.

Thanks
Barb:)

Gary Asthenia wrote:

> Dear all,
> As some of you may be aware from previous e-mails I am currently
> immunostaining FFPE sections to identify blood vessels.
> Does anybody have a good reason why on a protocol I have been shown,  the
> sections are treated with 0.2% proteinase (protease I think) for 8 mins at
> 37 degrees, immediately followed  after washing by the more conventional Ag
> retrieval method using trypsin.
> Any help and advice gratefully rece