Rapid blotting of IgG to nitrocellulose with minimal IgM contamination

A rapid method is described for the non-electrophoretic transfer of IgG from 0.5 mm thick agarose gels to nitrocellulose. Since the agarose gels are attached to a solid support, the blot is unidirectional. However, 90% of the IgG is transferred in 10 min with no visible loss of resolution. In this procedure, less than 2% of the IgM antibodies are transferred from the gel to the nitrocellulose membrane. Therefore, this technique can be used in IgG spectrotype analysis or antigen-specific assays without the prior removal of IgM antibodies. Approximately 5-6 h are needed to run the gels, blot, and develop the protein pattern with double-antibody immunoperoxidase staining.