Analysis of Mass Spec data (dashed-line) of fractions stained with Cytokeratin 19 MS-QAVA™ monoclonal antibody [Clone: KRT19/799] (solid-line), reveals that less than 2.3% of signal is attributable to non-specific binding of anti-Cytokeratin 19 [Clone KRT19/799] to targets other than KRT19 protein. Even frequently cited antibodies have much greater non-specific interactions, averaging over 30%. Data in image is from analysis in Jurkat, U202 and HeLa cells.