Proteins identified in immunodepleted sera. Venn diagrams showing the number of total proteins identified by MS/MS (≥ 95% confidence) in immunodepleted sera. (A) Proteins identified in the three sets of sera depleted by the IgY12 HPLC column. (B) Proteins identified in sera depleted by the MARS, IgY12 spin, and IgY12 HPLC columns. Identified proteins are listed in Additional file 2, Table S2.