College of Science and Engineering, Kanazawa University Azuma Taoka
Phase contrast microscopy video demonstrating magnetotaxis of the magnetically-enriched giant rod-shaped magnetotactic bacteria GRS-1 collected from a fresh water pond in Kanazawa, Japan. GRS-1 is the largest single-celled magnetotactic bacteria reported to date (~13 ?m by ~8 ?m). It swims toward the south pole of a bar magnet in a helical trajectory. Prior to the start of the movie the south pole of a bar magnet was placed next to the drop and GRS-1 cells swam to the edge of the drop. At three seconds into the movie, the magnetic field is reversed. Immediately the cells swim away from the edge of the drop. At eight seconds into the video, the magnetic field is reversed again and the cells swim toward the south end of the magnet.
(2014.08.02)