2D gel Western blot of a bovine SERPINA3 enriched fraction. High Mr fraction is eluted from a bovine diaphragma crude extract after gel filtration on a Sephadex G100 column, separated on 2D gel electrophoresis and hybridized with specific polyclonal antibodies. Arrows indicate the position of the two first characterized serpins bovSERPINA3-1 and bovSERPINA3-3. Note the linear alignment of spots corresponding to a different extent of phosphorylation of isoforms running with similar Mr on the second dimension. For more detail see the Methods section.