I have seen those concentrations in the literature as well. May want to see if Jefferson and Kimball are using similar concentrations.

Thanks...i saw a paper with 10mM but the response didt change that much thanks..

This is a tricky issue in C2C12s. See the paper in the link

http://www.ncbi.nlm.nih.gov/pubmed/?term=van+loon+and+c2c12

General protein synthesis isn't increased in response to leucine in such a way that can be measured by 35SMet incoroporation. I think that this replicates a number of other studies too (can't remember who done those now though) but its pretty consistent.

Lee.

Thanks Dr Hamilton