A SIMPLE LIGHT-SCATTERING METHOD TO ASSAY MAGNETISM IN MAGNETOSPIRILLUM GRYPHISWALDENSE

A simple optical method was developed for assaying cellular magnetism in culture samples of magnetic spirilla, Cells are aligned parallel to the field lines in a magnetic field, resulting in a change in light s cattering. The ratio of scattering intensities at different angles of magnetic field relative to the light beam (C-mag) is used to character ize the average magnetic orientation of the cells. C-mag was found to be well correlated with the average number of particles in different m agnetic cell populations. Thus, estimations of magnetosome content can be made using magnetically induced differential light scattering. The method provides a fast and sensitive tool for monitoring the magnetit e formation in growing cultures of Magnetospirillum gryphiswaldense.