Quantitative electrophoretic transfer of polypeptides from SDS polyacrylamide gels to nitrocellulose sheets: a method for their re-use in immunoautoradiographic detection of antigens.

Polypeptides (233 micrograms) from brain synaptosomes resolved in SDS 7.5%--15% polyacrylamide gradient gels were electrophoretically transferred quantitatively to nitrocellulose sheets at 3 V/cm for 21 h in the following buffer: 25 mM Tris-192 mM glycine, pH 8.3/20% methanol/0.1% SDS. After immunoautoradiographic detection of antigens on this nitrocellulose replica with either rabbit anti-rat cerebrum immunoglobulins or a mouse monoclonal antibody to a rat synaptosomal protein, the antibody and [125I]protein A were removed from the replica by treatment with 8 M urea, 0.1 M 2-mercaptoethanol, and 5 mg/ml BSA at 60 degrees C for 1 h. The replicas were successfully re-used by re-exposing them to the antibody and [125I]protein A.