  Protein solubilization for two-dimensional electrophoresis (2DE) has to break
molecular interactions to separate the biological contents of the material of
interest into isolated and intact polypeptides. This must be carried out in
conditions compatible with the first dimension of 2DE, namely isoelectric
focusing. In addition, the extraction process must enable easy removal of any
nonprotein component interfering with the isoelectric focusing. The constraints
brought in this process by the peculiar features of isoelectric focusing are
discussed, as well as their consequences in terms of possible solutions and
limits for the solubilization process.
