Protein blotting in uniform or gradient electric fields.

Experimental data and computer mapping were used to analyze electric fields generated by a variety of electrode arrays in protein blotting apparatus. Asymmetric electrode arrays were found to generate nonuniform fields that effected uneven transfers of 125I-labeled albumin from gels to nitrocellulose membranes. Symmetric arrays with multiple (four), independent wire electrodes, supplied individually with electric current, generated the most uniform fields and effected the most even transfers of the test protein. With multiple independent electrodes, gradient electric fields can be generated in which differences in electrophoretic elution between large and small proteins can be eliminated. Transfer apparatus with either uniform or gradient electric fields are expected to improve qualitative results and make possible quantitation of protein blotting.