Electrophoretic protein separations. A: Control- (lanes 1,2) and ovarian cancer-pool (lanes 3,4) serum samples were separated by protein electrophoresis before (lanes 1,3) or after (lanes 2,4) depletion for abundant proteins by cibacron blue and detected by coomassie blue straining. B-C: Control- and ovarian cancer-pool serum depleted for abundant sequences were immunoprecipitated with biobodies selected for specific binding to case-pool serum. The products of elution from control sera (B lane 2, and C) and ovarian cancer (B lane 1, and D) were separated by 1-D (B) or 2-D (C,D) protein electrophoresis and detected by silver staining. In the 2-D gels, the immunoprecipitates were focused over a pH3 to pH10 range and run on a 10% acrylamide gel. The circle indicates the region where PEBP1 was found in patient serum (D) but not in control serum (C).