Used in biomedical research to measure the concentration of follistatin in biological samples such as serum, plasma, or cell culture supernatants. It is commonly applied in studies related to reproductive health, muscle development, inflammation, and metabolic disorders. Researchers use this kit to understand the role of follistatin in regulating activin and other members of the TGF-beta superfamily. It supports investigations in endocrinology, oncology, and regenerative medicine where follistatin levels may influence disease progression or treatment response.