Gene that Induces a Magnetic Signature in Cells Found

A team of scientists have found a way to make human cells produce magnetic nanoparticles by introducing a gene from bacteria. The gene MagA was tested in human kidney cells, though the investigators believe that it will probably be most useful in tracking cell movement in transgenic animals via MRI.

“MagA can be thought of as the equivalent of green fluorescent protein but for magnetic resonance imaging,” says Xiaoping Hu, PhD, professor of biomedical engineering at Emory University and the Georgia Institute of Technology. Dr. Hu anticipates that MagA could find similar applications to green fluorescent protein, with the advantage that magnetic fields can penetrate tissues more easily than light.

MagA comes from magnetotactic bacteria, which can sense the Earth's magnetic field. It encodes a protein that transports dissolved iron across cell membranes. When put into animal cells, MagA triggers the accumulation of lumps of iron oxide a few nanometers wide, the researchers explain. MagA appeared to be nontoxic.

Other researchers from Emory University School of Medicine and Yerkes National Primate Research Center contributed to this study. The results are published in the June issue of Magnetic Resonance in Medicine.