protein quantification

Hi All,

I am new to worm protein isolation and had a few questions about how many worms one should have to get adequate conc. of protein to actually see a moderately abundant protein with antibody with western. Secondly, what type of assay do you use for quantification? I tried doing bradford assay but saw negative values suggesting that protein conc was too low. I used SDS in my sample buffer, could that have caused a problem with the assay?

Any suggestions would be helpful.
Thanks

The Wikipedia entry for Bradford assay explains how SDS (and other detergents) affect the results.