Related Experiment Video
Updated: Jun 27, 2026

Enhancing Efficiency and Radiolabeling Yields of Carbon-11 Radioligands for Clinical Research Using the Loop Method
Published on: December 20, 2024
Carbon-11 Production: Communication, Operations, Maintenance, Troubleshooting, and Analysis for Maintaining
Simon K Joseph1, Andrew Tavare2, Kiara Thomas1
1Department of Radiology, New York University Grossman School of Medicine, 660 First Avenue, Room 240, New York, NY 10016, USA.
Abstract:
Incorporation of carbon-11 radiotracers for positron emission tomography (PET) imaging requires close coordination between cyclotron operation, radiochemistry production, quality control, and clinical administration. A persistent challenge exists is the minimization of the carbon-12 isotopologue mass of the radiotracer, which reduces molar activity and can compromise PET image quality. This challenge can be particularly acute at facilities where cyclotron operation and carbon-11 radiochemistry are realized by separate organizations with distinct operational priorities. Here, we describe how the Radiochemistry Group at New York University Grossman School of Medicine and Siemens Healthineers have developed an integrated operational framework for consistent, high-quality carbon-11 production within an academic-industry partnership. Cyclotron target maintenance and conditioning protocols, remote chemistry module maintenance schedules, a validated radio-HPLC method (UV LOD = 0.9 µg/mL, UV LOQ = 3.0 µg/mL) for trending methyl iodide isotopologue mass, and structured inter-team communication protocols are presented in this manuscript. Quality analysis demonstrates molar activities consistently exceeding the recommended minimum of 40 GBq/µmol for reversibly binding radiotracers used in human PET studies. This work is intended as a practical resource for radiochemists, cyclotron engineers, and facility managers working to establish or improve institutional carbon-11 programs.
Related Concept Videos
¹³C NMR: Distortionless Enhancement by Polarization Transfer (DEPT)
Chemical Ionization (CI) Mass Spectrometry
Carbon-13 (¹³C) NMR: Overview
¹³C NMR: ¹H–¹³C Decoupling
A broadband decoupling technique is used to simplify these complex, sometimes overlapping, signals. Broadband decoupling relies on a...
Reaction Stoichiometry
Chemical Shift: Internal References and Solvent Effects
The internal reference compound generally used in NMR spectroscopy is tetramethylsilane (TMS). TMS is preferred because it is chemically inert, soluble in NMR solvents, and easily removable. Also, the highly shielded methyl protons in TMS yield an intense...

![Technical Aspect of the Automated Synthesis and Real-Time Kinetic Evaluation of [11C]SNAP-7941](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59557.jpg&w=3840&q=50)