Used in immunological research to quantify levels of interleukin-33 in biological samples such as serum, plasma, or cell culture supernatants. Enables study of IL-33's role in inflammatory responses, allergic diseases, and immune regulation. Commonly applied in preclinical studies involving asthma, atopic dermatitis, and autoimmune conditions. Supports evaluation of therapeutic interventions targeting the IL-33/ST2 pathway. Suitable for use in laboratory settings only, not for diagnostic or clinical use.