Elimination of the detection of an artefactual 65 kDa keratin band from immunoblots

Contamination of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) samples with skin keratin has produced a recurrent problem of artefactual bands when highly sensitive detection methods, such as silver staining, have been used. Such an artefact also can be a problem in immunoblots because some sera appear to contain antibodies that react with a human skin keratin. A simple method for the removal of these antibodies with keratin immobilized on an affinity chromatography substrate is described.