MTT ASSAY HELP - (Jun/03/2008 )

I am doing MTT assay for GCSF with M NFS 60 cell lines
I am using the cell concentration 70,000 cells/ml and NIBSC std GCSF range 50 IU - 12.5 IU /50 microliter
but i am not getting the gradation in OD values with different conc of GCSF
Can anyone help me in solving my problem
Its very urgent

Thanks and Regards

I don't fully understand what you're trying to do, but I'd recommend to do a standard curve with the cells ranging from x-y, and find the linear range of the assay. This validates the assay and you can use it to measure cell number (activity) within this range. Maybe you already did that, I dunno.

Is it that you're getting no growth, or no inhibition?