Synthesis of Radiolabeled Compounds

Based on expertise that has been accumulated since the start of contract custom synthesis in 1955, we synthesize radio isotope (RI)-labeled and stable isotope (SI)-labeled compounds. Please ask about non-labeled compounds such as metabolite references and control compounds.

Chemical Synthesis

To synthesize the compound of interest, we select either the RI or SI method to synthesize a labeled compound.
We seek to perform quick synthesis not only on our own but also through alliances with our other partners both in Japan and overseas.


  • Curachem Inc. (Korea)
  • RC Tritec AG (Switzerland)
  • ALSACHIM (France)


If your labeled compound in you facilities or at our site is degraded and its purity is decreased, we will purify it by request.

Quality Control

We will provide synthesized labeled compounds with a Certificate of Analysis (CoA) in which serial number, labeled position, specific activity, radiochemical purity and precautions for storage are described.
RI-labeled compounds are more likely to decrease its purity due to radiation effect than non-labeled compounds. We will analyze purity of your labeled compound in storage by TLC and HPLC methods at your request, and then issue a CoA.
The other instruments available for measurement include 1H-NMR, MS and IR. These Purity tests can be performed in compliance with the GLP standard as required.


We will prepare a report describing actual synthesis/purification procedures to submit at your request.

Consultation Services

Taking advantage of our considerable experience and performance, we can offer labeled position, labeling isotope, specific activity and amount that meet your intended use of the labeled compound to be synthesized.
Availability of raw material and intermediates is to be considered as well.

Inquiry for Custom Synthesis

Please give us the following information at your inquiry.

  • Name of compound
  • Structural formula and labeled position
  • Molecular weight
  • Isotope
  • Necessary amount (e.g.: 37 MBq)
  • Preferable specific activity (e.g.: 1.85 GBq/mmol)
    If it is solution, please add preferable radiation concentration to the above information (e.g., 37.0MBq/mL)
  • Radiochemical purity
  • Presence or absence of isomer
  • Aliquots at release
  • Analytical method: HPLC, 1H-NMR and MS
  • Presence or absence of provision of synthesis method
  • Presence or absence of literatures
  • Presence or absence of raw material and intermediate