protein quantification - protein expression (Dec/15/2001 )

i want  to know the level of expression of the recombinant protein that was expressed in e.coli bl21de3 expressed under t7 promoter.

T7 pol based expression is good choice.
However, protein expression level is totally depends on your cDNA: interest protein.
In my lab. If T7 based expression in BL21(DE3) is bad, we use pQE expression vector(Qiagen) which is most powerful system that I ever used.
Unfortunately, however, If your cDNA is from eukaryote, the chance is 50%.
Good luck!