Well, I would optimize my WB settings (gel, run, but especially Abs, etc) doing a titration with known input amounts of albumin for example, the most abundant plasma/serum protein. Then if this is reliable and reproducible I would choose only one concentration to run in each of your WB as a positive control.

Thank you! This is what I was thinking to do: comassie staining and imagej analysis of all the lanes to check for the total amount of protein load!