Immunoelectrophoresis is a technique that separates proteins on the basis of both their net charge (and so their movement in an electric field) and on the response of the immune system to the proteins. The technique is widely used in both clinical and research laboratories as a diagnostic tool to probe the protein composition of serum.

Petr Nikolaevich Grabar, a French immunologist, devised the technique in the 1950s. In essence, immunoelectrophoresis separates the various proteins in a sample in an electric field and then probes the separated proteins using the desired antiserum.

The most widely used version of the technique employs an apparatus, which consists basically of a microscope slide-sized plate. The plate is the support for a gel that is poured over top and allowed to congeal. The construction of the gel can vary, depending on the separation to be performed. Agar, such as that used in...