Micropurification and two-dimensional polyacrylamide gel electrophoresis of immunoglobulins for studying the clonal diversity of antigen-specific antibodies

Presented here is a simplified method for purifying antigen-specific antibo dies and analysing them by two-dimensional polyacrylamide gel electrophores is (2D-PAGE). For this procedure, specific immunoglobulins (Ig) are bound t o resin beads coated with antigen and, in the presence of sodium dodecyl su lphate and dithioerythritol, loaded directly onto isoelectric focusing stri ps for 2D-PAGE analysis. This technique bypasses antigen-specific Ig elutio n and concentration and therefore minimises antibody loss and simplifies sa mple preparation. Because of its high sensitivity, this technique permits c lonal analysis of samples containing small quantities of Ig. We studied Ig anti-tetanus toroid (TT) and IgG in sera from several sources. The resultin g oligoclonal Ig anti-TT patterns contrasted with the polyclonal patterns o f total IgG visualised after 2D-PAGE analysis of the respective serum sampl es. (C) 1999 Elsevier Science B.V. All rights reserved.