[Immunofixation in agarose gel for the identification of monoclonal immunoglobulins].

Immunoelectrophoresis is the usual method for identifying abnormal bands detected by zone electrophoresis. In the last few years, a new technique has appeared, that of immunofixation. This method involves an antibody-antigen precipitation reaction in an electrophoretic strip. The aim of the present study was to compare immunofixation (IFX) and immunoelectrophoresis (IEP) of 101 sera with one or more homogeneous bands upon serum protein electrophoresis: among them 97 bands were subsequently characterized by IFX on agarose gel, and only 50 by IEP. IF appears to be a more sensitive technique for characterizing M-components, especially those with multiple bands. While more rapid than IEP, this new procedure does not seem appropriate for routine use.