immunohistochemistry question

[mark]

Amy E. Loercher wrote:
> We think we're
> detecting cytokine that has bound to the cell's surface, but is not
> produced by the cell. R&D, the company that produces the MAb we're using,
> has said this is a possibility. Does anybody know a way to control for
> this? Right now, I'm thinking about either trypsinizing the cells prior
> to fixing to remove everything from the surface, or maybe running a
> sample without saponin and comparing the intensity of staining. 


Both approaches sound reasonable and reasonably easy to do so I would try 
both.