Enzyme Immunoassay for the quantitative determination of Atezolizumab in serum, plasma and cell culture supernatant. Atezolizumab (trade name Tecentriq) is a fully humanized, engineered monoclonal antibody of IgG1 isotype against the protein programmed cell death-ligand 1 (PD-L1). In 2015, it was in clinical trials as an immunotherapy for several types of solid tumors. It was under investigation by Genentech/Roche. In April 2016, Roche announced that atezolizumab had been granted fast track status for lung cancer by the FDA.In May 2018, Tecentriq was in combination with Avastin and standard chemotherapy for some patients with lung cancer was granted priority review. Krishgen PK kits, developed using the innovator drug as calibrator, are used for the quantitation of serum protein drug levels, and can be used for biosimilar and generics research as well. About the kit: - Uses anti-idiotypic antibodies sourced from our vendor partner in the US, which ensures higher specificity, and low cross reactivity. - Recovery rates are between 85 - 115% - Ready to use with a standard protocol with break-apart pre-coated wells - Validated as per US FDA guidelines for Bioassays - Optimized for matrix effects to ensure higher sensitivity. - Shelf life: 1 year The method employs the quantitative sandwich enzyme immunoassay technique. Antibodies to Atezolizumab are pre-coated onto microwells. Samples and standards are pipetted into microwells and human Atezolizumab present in the sample are bound by the capture antibody. Then, a HRP (horseradish peroxidase) conjugated anti-Atezolizumab antibody is pipetted and incubated. After washing microwells in order to remove any non-specific binding, the ready to use substrate solution (TMB) is added to microwells and color develops proportionally to the amount of Atezolizumab in the sample. Color development is then stopped by addition of stop solution. Absorbance is measured at 450 nm.