Bevacizumab (Trade name Avastin®) is a recombinant humanized monoclonal antibody that blocks angiogenesis by inhibiting vascular endothelial growth factor A (VEGF-A). VEGF-A stimulates angiogenesis in a variety of diseases, including cancer. Bevacizumab was the first clinically available angiogenesis inhibitor in the United States. Bevacizumab was approved by the U.S. Food and Drug Administration (FDA) for certain metastatic cancers. It received its first approval in 2004, for combined use with standard chemotherapy for metastatic colon cancer. It has since been approved for use in certain lung cancers, renal cancers, ovarian cancers, and glioblastoma multiforme of the brain. It had been approved for breast cancer, but that approval was withdrawn when later studies showed no evidence of effectiveness The Bevacizumab ELISA kit is designed to measure free Bevacizumab with high specificity and sensitivity. This assay employs the sandwich enzyme immunoassay technique. A precoated anti-Bevacizumab 96 well plate is provided. Calibrator, quality control samples and test samples are pipetted into the appropriate wells. Bevacizumab present in biological matrices is bound by the immobilized capture antibody. After washing away any unbound substances, enzyme linked detection antibody is added to the wells. The plate is washed to remove any unbound antibody-enzyme reagent and a substrate solution is added to the wells for color development. The color development is proportional to the amount of Bevaciuzumab present in test samples and the concentration is calculated from the standard series.