Rheumatoid arthritis is an autoimmune inflammatory joint condition which primarily affects the synovium of joints, characterised by synovial inflammation as well as articular cartilage and underlying bone destruction. Within this study, the proteomes of serum obtained from rheumatoid arthritis patients, and appropriate human controls, were analysed using liquid chromatography-tandem mass spectrometry. ProteoMiner™ equalisation columns were used to deplete high abundant proteins and reduce the protein concentration dynamic range.