Brenda,
Biotin block is not the same as protein block.  To block endogenous biotin you need to use avidin and biotin.  I always used these as a biotin block kit from DAKO but
you could probably buy it from Sigma and make it yourself.
Patsy Ruegg

Brenda D Begg wrote:

> Hi Guys
> Thanks for your reply Greg D. Is a biotin block the same as a protein block ie. could I use 0.5% casein.Or can you give me an example of a biotin block I could use.
>
> Brenda B