The company Referenzsubstanzen für Diagnostik und Arzneimittel­forschung, also known as Endotherm, specializes in providing reference substances for diagnostic and pharmaceutical research. They offer a wide range of over 1,000 substances for use in research and diagnostics, and also provide contract synthesis services to develop new diagnostic procedures and pharmaceuticals. The company prioritizes quality, having been certified according to the ISO 9001:2015 standard, and focuses on delivering high-quality products and services to support research and development in the pharmaceutical and diagnostic industries.