A Centrifuge Polarizing Microscope (CPM) That Enables the Visualization of Intracellular Structures Under High Centrifugal Forces.

The mitotic spindle consists of aligned filaments of dynamic microtubules that faithfully segregate mitotic chromosomes. This view of the mitotic spindle was initially established by detecting weak birefringence of the aligned filaments, which was realized by developing polarized light microscopy (Inoué S, Chromosoma 5:487-500. https://doi.org/10.1007/bf01271498 , 1953). Inoué et al. developed a centrifuge polarizing microscope (CPM) (Inoué S et al., J Microsc 201:341-356. https://doi.org/10.1046/j.1365-2818.2001.00850.x , 2001; Inoué S et al., Centrifuge microscope capable of realizing polarized light observation (US Patent: US1907803A), 1999) to further understand the structural and physical basis of the functional positioning of centrosome-based structures (including the mitotic spindle) inside living cells. This chapter describes the procedure for observing biological specimens using CPM by focusing on Caenorhabditis elegans embryos.