This procedure works well with samples producing discrete monoclonal protein spikes and is easier to perform than sIFE . However, IFE may still be required as a complementary method to determine the monoclonal protein type in a number of situations . These include detection/typing of: 1) monoclonal sFLCs of the same type as the characterised monoclonal intact immunoglobulin; 2) multiple monoclonal proteins, e.g. biclonal gammopathies or oligoclonal banding; 3) “hidden” monoclonal proteins, e.g. small (<3 g/L) IgA or IgM monoclonal proteins that co-migrate with other serum proteins in the β-region; and 4) IgD and IgE monoclonal proteins.