Protein preparations specifically prepared for standardising electrophoresis methods and protocols. Substantially free from non-protein agents such as nucleic acids, detergents, salts, lipids and other common laboratory agents, the protein preparation has low conductivity (<50 μs). Supplied as dry protein pellets, simply re-hydrate and use. Proteomic protein sample controls are available for animal cells, E.coli, yeast, plant or as a control set that contains one 2 mg vial of each.