Used in immunological research to detect and quantify mouse IgG4 levels in biological samples such as serum, plasma, or cell culture supernatants. Commonly applied in studies involving immune response modulation, allergic inflammation, autoimmune diseases, and vaccine development. Helps researchers assess Th2-biased immune responses, as IgG4 in mice is associated with anti-inflammatory and regulatory immune functions. Widely used in preclinical studies to evaluate therapeutic interventions and monitor changes in humoral immunity.