[Histonet] HELP!!! peroxidase blocking on HCC paraffin sections!!!!

[Victor Wong]

Hi all,
   
  Last time I tried to block endogenous peroxidase with 0.3% hydrogen peroxide for 15 minutes but it came out a lot of background.  Then I tried to block with 3% in PBS for 10 and 30 minutes.  The background staining was greatly reduced esp. in that treated for 30 minutes.  But the positive staining was also muchly reduced.  Since I have no spared slides left, I cannot make others trial to massage the blocking conditions.  I felt very frustrated and now I am seeking help from you folks.  I use the DAKO's Envision+ kit therefore it should not be the endogenous biotin's problem.  I also want to know the rationale behind the H2O2 on blocking the peroxide and the visualization of chromogen.  Tons of thanks.
   
  Victor

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