The application of isoelectric focusing to routine screening for paraproteinaemia

We present a scheme for routine screening of patients' sera for monoclonal immunoglobulin by isoelectric focusing in agarose gels. Using this method combined with immunofixation, we have been able to detect monoclonal immunoglobulin in the sera of patients, and to identify the isotype of the immunoglobulin when conventional techniques such as zonal and immunoelectrophoresis have yielded equivocal results.