High-resolution magnetic force microscope images of a magnetic particle chain extracted from magnetic bacteria AMB-1

Bacterial magnetic particles were observed by an atomic force microscope (AFM) and a magnetic force microscope (MFM). The chain of magnetic particles was extracted from the bacteria with little disturbance to their alignment by a new preparation method. Magnetic bacteria cells were broken using an NaOH/ethanol solution. Cell debris was washed away in order to leave the magnetic particle chains, which were held on the glass surface by a magnet. In both AFM and MFM images, individual magnetic particles could be clearly observed. The MFM image showed that the particles aligned their magnetized axes along the chain.