CAS 1255639-56-5 appears in our catalog under these names: Estriol-2,3,4-13C3, ESTRIOL-2,3,4-13C3, 99 ATOM % 13C, 97% &, Estriol-13C3. Offered by: Biosynth, Sigma-Aldrich, MedChemExpress. Available pack sizes: 1mg, 1000UG, 100UG, 250UG, 500UG, 100 μg.