The OAS3 (2'-5'-oligoadenylate synthetase 3) antibody is a tool used to study the OAS3 protein, a key component of the innate immune response against viral infections. OAS3 belongs to the oligoadenylate synthetase family, which is interferon-inducible and activated by double-stranded RNA (dsRNA) produced during viral replication. Upon activation, OAS3 catalyzes the synthesis of 2'-5'-oligoadenylates (2-5A), which bind to and activate RNase L, triggering RNA degradation to inhibit viral proliferation. OAS3 is the largest isoform in the OAS family, with distinct structural features and higher enzymatic activity compared to OAS1 and OAS2. It is expressed in various tissues, including immune cells, and plays roles beyond antiviral defense, such as modulating inflammation and cell death pathways. Research using OAS3 antibodies has linked its dysregulation to autoimmune diseases (e.g., systemic lupus erythematosus), neurodegenerative disorders, and cancer progression. These antibodies are essential for detecting OAS3 expression levels, localization, and interactions in experimental models, aiding in understanding its role in viral pathogenesis (e.g., hepatitis C, SARS-CoV-2) and immune regulation. Commercial OAS3 antibodies are typically validated for applications like Western blotting, immunofluorescence, and ELISA, with specificity confirmed via knockout controls.