Used in research and diagnostic applications to detect glutamic acid decarboxylase 65 (GAD65), an enzyme associated with autoimmune neurological disorders and type 1 diabetes. This reference antibody serves as a standardized tool for immunoassays, enabling consistent measurement of anti-GAD65 autoantibodies in patient sera. It is particularly valuable in studies of stiff-person syndrome, cerebellar ataxia, and other GAD65-related autoimmune conditions. The antibody supports assay development, validation, and quality control in clinical laboratories and research settings. Due to its well-characterized specificity, it is used as a benchmark for comparing patient antibody responses and evaluating new diagnostic methods.