C/D/N ISOTOPES (Popularity: )

Quite a large listing of deuterated compounds and Carbon-13 and Nitrogen-15 labelled compounds. In English ...

Cambridge Isotope Laboratories (Popularity: )

Manufacturer of stable isotope labeled compounds and some fine deuterated solvents too.

Silantes GmbH (Popularity: )

Stable isotope labeled biopolymers (H2, C13, N15)

Medical Isotopes, Inc. (Popularity: )

Nearly a complete line of enriched biochemicals. Nice selection of fatty acids, enriched with C13.