Electrofocusing followed by gradient electrophoresis: a two-dimensional polyacrylamide gel technique for the separation of proteins and its application to the immunoglobulins.

A two-dimensional polyacrylamide gel technique for the separation of proteins is described. Electrofocusing in a 3.5% polyacrylamide gel is followed by electrophoresis through a 4-24% concave polyacrylamide gel gradient. The method resolves a large number of serum proteins and produces highly reproducible patterns. It is particularly useful for studies involving proteins of high molecular weight, such as alpha2-macroglobulin, beta-lipoprotein and IgM. The application of the technique to the immunoglobulins in pathological sera is reported.