Related Experiment Video
Updated: Jan 30, 2026

Solid Phase 11C-Methylation, Purification and Formulation for the Production of PET Tracers
Published on: October 24, 2019
A simple and efficient automated cGMP-compliant radiosynthesis of [11 C]metomidate using solid phase extraction
Mitja Kovac1, Tunde Miklovicz1, Lei Li1
1Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, CB2 0QQ, UK.
None:
[11 C]metomidate ([11 C]MTO) is a radiotracer widely used to detect disorders of adrenocortical origin by positron emission tomography (PET) imaging. [11 C]MTO PET/computed tomography (PET/CT) is considered a sensitive and specific noninvasive alternative to adrenal vein sampling (AVS) in the management of primary hyperaldosteronism (PHA). Herein, we report a reliable automated procedure for the routine manufacturing of [11 C]MTO in current good manufacturing practice (cGMP) conditions on the commercial Synthra MeIPlus Loop Vessel synthesizer. The method is based on a combination of the captive-solvent 11 C-methylation of the carboxylate salt 1b of the MTO precursor 1a followed by solid phase extraction (SPE) cartridge purification methodology, which substitutes HPLC purification of the crude reaction mixture. Starting from 45 GBq [11 C]CO2 at the end of bombardment (EOB), 3 GBq of pure [11 C]MTO was produced in 18 minutes with 12% decay corrected radiochemical yield (RCY) at the end of synthesis (EOS) and with the modest molar activity of 13 GBq/micromol at the time of application. Each dose produced met all established quality control (QC) criteria. The method can easily be implemented into other commercial automated radiosynthesizers for manufacturing carbon-11 labeled radiotracers.
Related Concept Videos
Structures of Solids
Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
Phase Diagrams
Phase Transitions
Network Covalent Solids
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
Phase Transitions: Sublimation and Deposition

![An Automated Radiosynthesis of [68Ga]Ga-FAPI-46 for Routine Clinical Use](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F66708.jpg&w=3840&q=50)