Question:  since the avidin/biotin block is done AFTER a normal serum
blocking step, how much biotin could potentially be in a normal serum,
say goat serum?  Obviously some tissues are the main culprit for endog
biotin, but are you adding it back with normal serums sometimes used
in buffers or diluents of secondaries, etc. 

AND has anyone used goat antibiotin-HRP to detect the biotinylated 
secondary, or even a biotin conjugated primary?  It is used for ELISA
technics, but wondered what kind of success people have with this antibody
on tissues?  

So many questions--------------

Gayle Callis