Human anti trastuzumab, clone AbD18018_hIgG4_Pro, is a paratope specific, high affinity, anti-idiotypic antibody that specifically recognizes the monoclonal antibody drug trastuzumab and inhibits it binding to its target. It is a fully human recombinant monoclonal antibody with IgG4 isotype. The antibody can be used to measure the levels of trastuzumab and biosimilar products in bioanalytical assays.Anti-trastuzumab antibody clone AbD18018 has been converted to human IgG4 isotype to offer assay developers increased flexibility in assay design. When used as an ELISA detection antibody, a secondary anti-human IgG4 antibody is required, which can be labeled according to the requirements of the user"s preferred assay platform.The antibody can be used to develop a pharmacokinetic (PK) bridging assay to measure free drug in preclinical research and clinical trials using patient sera. Antibody clones AbD16712 (HCA166) or AbD18141 (HCA169), both monovalent Fab format, are recommended as the capture antibody. Detection can be performed using clone AbD18018_hIgG4_Pro and an HRP conjugated anti-human IgG4 secondary antibody (MCA2098P).This clone is also available as an IgG1 isotype in both a purified unconjugated format (HCA177) and directly conjugated to HRP (HCA177P). Trastuzumab, also known as Herceptin®, is a drug used in the treatment of HER2 postive breast cancer and other HER2 over-expressing cancers including HER2-positive metastatic cancers of the gastrointestinal tract. Trastuzumab binds to the HER2 (or c-erbB2) proto-oncogene, an EGF receptor-like protein found on 20-30% of breast cancer cells. The binding leads to antibody mediated (complement mediated) killing of the HER2 positive cells.View a summary of all anti-trastuzumab antibodies