Detection and identification of monoclonal components: immunoelectrophoresis on agarose gel and immunofixation on...

Immunofixation on cellulose acetate has been compared with immunoelectrophoresis on agarose gel. We studied 90 sera containing monoclonal components and 10 containing polyclonal immunoglobulins according to agarose gel screening electrophoresis. Results by the two methods agreed about 80% of the time for monoclonal components in concentrations exceeding 1-2 g/L. Immunofixation appeared more sensitive, but it is more susceptible to technical artifacts. Immunofixation may be adopted as a first-step method for easier cases, but it should be supported by immunoelectrophoresis for difficult cases, such as when there is an uncertain presence of monoclonal components at screening electrophoresis or presence of more and (or) small bands of monoclonal components.