The Antibody Characterization Lab (ACL), an intramural reference laboratory located at the Frederick National Laboratory for Cancer Research in Frederick, Maryland, thoroughly characterizes monoclonal antibodies or other renewable affinity binding reagents for use in cancer related research. All antibodies are characterized (a non-exclusive list, and as recommended by the International Working Group on Antibody Validation) using Enzyme Linked ImmunoSorbent Assay (ELISA), Western blot (recombinant/cell lysate/native), Surface Plasmon Resonance (SPR), SPR pairing, Immuno Mass Spectroscopy, Reverse Phase Protein Array (RPPA), and Immunohistochemistry (IHC). It is the broad range of specialized assays, the use of standardized methods, and the complete characterization data (positive and negative results) made available to researchers that make this a unique resource. The ACL also has access to the NCI-60 human cancer cell lines that are a unique resource not widely available to outside firms. The availability of data and methods allows researchers to select appropriate antibodies for their particular use and provides researchers with tools to quality control materials for experiments. All reagents are freely available to the research community, along with their associated characterization data and standard operating procedures on the web.