Zhao Luze, Wu Dan, Wu Long-Fei, Song Tao
Bioelectromagnetic Lab, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China.
J Biochem Biophys Methods. 2007 Apr 10;70(3):377-83. doi: 10.1016/j.jbbm.2006.08.010. Epub 2006 Sep 1.
A simple apparatus for measuring the magnetism of magnetotactic bacteria was developed with a common laboratory spectrophotometer, which was based on measuring the change in light scattering resulting from cell alignment in a magnetic field. A multiple coils were built around the cuvette holder of the spectrophotometer to compensate geomagnetic field and to generate two mutually perpendicular magnetic fields. In addition, we defined a novel magnetism parameter, R(mag), by modifying the definition of C(mag) to a normalized parameter with the culture absorbance obtained without application of magnetic field. The number of magnetosomes in each cell was determined by transmission electron microscopy to assess the relationship between the two magnetism parameters and the distribution of magnetosomes in the cells. We found that both R(mag) and C(mag) were linearly correlated rather with the percentage of magnetosome-containing bacteria than with the average magnetosome numbers, and R(mag) exhibited a better linearity than C(mag) with respect to the percentage of magnetosome-containing bacteria.
利用普通实验室分光光度计开发了一种用于测量趋磁细菌磁性的简单装置，该装置基于测量磁场中细胞排列导致的光散射变化。在分光光度计的比色皿支架周围构建了多个线圈，以补偿地磁场并产生两个相互垂直的磁场。此外，通过将C(mag)的定义修改为一个用未施加磁场时获得的培养物吸光度进行归一化的参数，我们定义了一个新的磁性参数R(mag)。通过透射电子显微镜确定每个细胞中的磁小体数量，以评估两个磁性参数与细胞中磁小体分布之间的关系。我们发现，R(mag)和C(mag)都与含磁小体细菌的百分比呈线性相关，而不是与平均磁小体数量呈线性相关，并且就含磁小体细菌的百分比而言，R(mag)比C(mag)表现出更好的线性关系。
