Used in immunological research to detect and quantify Proteinase 3 (PR3) in biological samples such as serum, plasma, and cell culture supernatants. Commonly applied in studies related to autoimmune diseases, particularly granulomatosis with polyangiitis (GPA), where PR3 is a major autoantigen. The kit enables researchers to measure PR3-specific antibody levels or monitor PR2 antigen concentration, supporting diagnosis development, disease activity assessment, and evaluation of therapeutic responses in preclinical models. Suitable for high-throughput screening and mechanistic studies involving neutrophil-mediated inflammation and vascular injury.