Hi Roberta,

The concentration may differ with respect to your study design (in vivo or cell culture, and even cell type). However, the antibody catalogue and similar articles may also reinforce. I have provided an example of these articles:

http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2567.1997.00360.x/epdf

Hope that it help you

I will use Invivogen IL1beta on microglial cells in vitro

 Anyway, thanks for your answer!