Used in laboratory research to measure thyroxine (T4) hormone levels in duck serum or plasma samples. Helps in studying thyroid function, endocrine health, and metabolic disorders in ducks. Commonly applied in veterinary research, poultry health studies, and environmental toxicology to assess the impact of pollutants on thyroid systems in avian species. Provides a sensitive and specific method for high-throughput screening in experimental and field studies.