Anti-Human CD19 (FMC63) Antibody (ICH1258-0.1mg)

Please refer to the specific buffer information in the hardcopy of datasheet or the lot-specific COA.

Anti-Human FMC63 (IB11) is a recombinant monoclonal antibody targeting human CD19, built on the well-characterised FMC63 clone in a human IgG1 kappa format. FMC63 is one of the most extensively studied anti-CD19 binders and is the source of the single-chain variable fragment used in numerous CD19-directed engineered cell therapies, making it a widely adopted reference reagent for CD19 detection, epitope-competition studies, and construct development. The human IgG1 kappa scaffold suits applications where a fully human framework and defined Fc are preferred, including flow cytometry, immunoprecipitation, ELISA-format binding assays, and functional in-vitro work with CD19-expressing B-lineage cells and CAR-T model systems. Supplied as a bulk, research-grade preparation with low endotoxin (research grade less than 1 EU/mg; ultra-low grade less than 0.5 EU/mg), it is intended for demanding cell-based and functional assays where endotoxin and lot-to-lot consistency matter. For research use only (RUO); not for diagnostic or therapeutic use. Provided at scale (milligram to gram) to support screening, assay development, and reproducibility across experiments. CD19 is a 95 kDa type I transmembrane glycoprotein of the immunoglobulin superfamily expressed throughout B-cell development, from the pro-B stage through mature B cells, and lost only upon terminal plasma-cell differentiation. It associates with CD21, CD81, and CD225 to form the B-cell co-receptor complex, where it lowers the threshold for B-cell receptor signalling by amplifying downstream PI3K and other pathways after antigen engagement. Its restricted, lineage-specific expression pattern and near-universal presence on B-cell malignancies have made CD19 a central target for immunotherapy, including antibody, bispecific, and chimeric antigen receptor (CAR) approaches. The FMC63 epitope, located in the extracellular region of CD19, is the binding determinant underlying many clinically deployed CD19-targeted constructs, which is why FMC63-based reagents are widely used to model and benchmark CD19 recognition.