Antigen retrieval problem

[biolearner]

Hi, eveyone,
I tried to do CD34 membrane antigen retrieval from paraffin embedded tissue section with microwave and enzyme methods, but just found these methods are not working. The protocols I used are as follows.
http://www.e-biotek.com/immunology/241- ... evals.html

I used the above methods successfully to retrive nuclear antigen from the same sections. I wonder if there are some chemical method I can use to retrive the membrane antigen.

Thank you in advance.