New antigenic determinants revealed on human IgG by binding to immunoblotting membranes [corrected]

During immunoblotting for detection of human IgG, rabbit antibodies to goat IgG reacted with human IgG, Fc fragments and gamma chains when these proteins were bound to nitrocellulose or Immobilon-P membranes. This reactivity could not be adsorbed with human IgG-agarose beads or blocked with fluid phase human IgG. It was readily abrogated with human IgG adsorbed to one of these membranes, indicating that new antigenic determinants were exposed and accounted for the cross-reactivity.