Hartmann Analytic GmbH - Supplier of radio-labeled chemicals, products for radiation protection. Also offers labeling-services and custom synthesis. STB Isotopes - Stable isotopes for science, medicine and industry, a list of some rare and unusual stable isotopes. Wellington Laboratories - Produces 12C and 13C halogenated reference standards of environmental concern, including chlorinated and brominated dioxins, furans, biphenyls and diphenyl ethers. Includes corporate and product details, online catalog and contacts. MDS Nordion - Radioisotope technology used to prevent, diagnose and treat disease. Products and services include nuclear medicine, radiation therapy for cancer, irradiation sterilization and food irradiation. Moravek Radiochemicals - Manufacturer of tritium and carbon 14 labeled radiochemicals for AIDS and cancer research. International Isotope Society - The IIS provides a forum for all chemists involved in radiochemical synthesis and analysis to obtain and share information outside of their immediate area of employment and expertise. PicoTrace - Equipment for trace element and isotope analysis. RITVERC GmbH - A producer and worldwide supplier of radioisotope products for science, industry, and medicine. Product list includes radiation sources, labelled compounds, stable isotopes, and radiopreparations. International Isotopes Clearing House, Inc. - Catalog listing of radioisotopes, 14C- and 3H-labeled compounds for medical research, 33P- and 125I- available. ViTrax Radiochemicals - Manufactures Tritium, Carbon-14, and Sulfur-35 radiolabeled products and offers custom radiosynthesis under cGMP. Omicron Biochemicals Inc. - Supplier of single, multiple and uniform stable isotope labeled saccharides and nucleosides (13C, 2H, 15N, 18O). Techsnabexport - Supplier of Russian-produced radioisotopes and labeled compounds. Isoflex - Stable isotopes for use in science, medicine and industry from Russian producers. Icon Services - Supplier of compounds labeled with stable isotopes. IsoSciences - Custom stable isotope labeling and small scale organic synthesis including the preparation of metabolites and PET precursors and standards. Isotec - A member of the Sigma-Aldrich family, manufacturer of stable isotope labeled compounds. Alsachim - Supplier of stable labelled drugs and metabolites including custom synthesis of multilabelled building blocks. Trace Sciences International - Supplier of stable isotopes including a complete range of enriched stable isotopes. Aptochem - Specialists in radiosynthesis, compound synthesis, bioanalysis and in custom synthesis of reference standards. Also specialists in analytical chemistry, including calculation of isotopic distribution. American Radiolabeled Chemicals Inc. - Offers more than 4,000 radiolabeled and unlabeled neurochemicals and biochemicals for life science research. CortecNet: Stable Isotopes - Provides various stable isotope products including amino acids, fatty acids, carbohydrates, isotopic gases and metal isotopes. U.S. DOE Isotope Production and Distribution - U.S. Department of Energy isotopes catalog. Quite an extensive list.