How to visualize bio-metals and bio-molecules simultaneously

May 3, 2013

Experimental gamma-ray system allows for visualizing multiple bio-metal elements simultaneously with PET scans of bio-molecules (credit: RIKEN)

Researchers from the RIKEN Center for Life Science Technologies have developed a new molecular imaging technology that enables them to visualize bio-metals and bio-molecules simultaneously in a live mouse.

This new technology will enable researchers to study the complex interactions between metal elements and molecules in living organisms.

Metal elements such as zinc, iron and copper are present in trace amounts in the body and play an important role in myriad biological processes including gene expression, signal transduction and metabolic reactions. Abnormalities in the behavior of these elements often reflect abnormalities in associated bio-molecules and studying them together can offer great insight into many biological processes.

Bio-molecules can be visualized in living organisms using positron emission tomography (PET), a widely used nuclear medical molecular-imaging technique. For bio-metal elements, Dr. Shuichi Enomoto, Dr. Shinji Motomura, and colleagues from the RIKEN Center for Life Science Technologies developed a gamma-ray imaging camera, enabling them to detect the gamma-rays emitted by multiple bio-metal elements in the body and study their behavior.

Results of the imaging experiment on a tumor-bearing mouse: (a) localization of the three lines of tumor cells; (b) localization of the labeled antibody (c) localization of Zn-containing injected radioactive agent (credit: RIKEN)

Their second prototype of the system, called GREIā€“II, enables them to visualize multiple bio-metal elements more than 10 times faster than before, and to do so simultaneously with positron emission tomography (PET).

In the study, the researchers were able to visualize two radioactive agents injected in a tumor-bearing simultaneously with an anti-tumor antibody labeled with a PET molecular probe agent.

This new revolutionary technology is expected to offer new insights into the relationships between bio-metal elements and associated bio-molecules, and the roles they play in diseases such as diabetes and cancer.


  • Shinji Motomura et al., Improved imaging performance of semiconductor Compton camera GREI makes for a new methodology to integrate bio-metal analysis and molecular imaging technology in living organisms, Journal of Analytical Atomic Spectrometry, 2013, DOI: 10.1039/C3JA30185K, in press