Used in immunological research to detect and quantify secretory IgG4 antibodies in biological samples such as saliva, mucosal secretions, and serum. This ELISA kit enables researchers to study immune responses in mucosal tissues, particularly in the context of allergic diseases, autoimmune conditions, and chronic antigen exposure. It is widely applied in clinical research to monitor IgG4 levels in patients undergoing immunotherapy, especially for allergies and parasitic infections. The kit supports high-throughput analysis and provides a reliable, sensitive method for measuring sIgG4, aiding in the understanding of IgG4's role in immune regulation and tolerance.