Fig. 1

Schema of cell fixation methods and phase-contrast images of TK6 cells on the bottom of a well in the 96-well plate. a Fixation by a conventional method using an isotopic condition. Cells in the well were centrifuged and fixed with isotopic paraformaldehyde (PFA). Then the cells were dehydrated with methanol and became attached to the bottom of the well. The method caused cells to shrink through dehydration, and MNi were placed very close to the primary nuclei, which could make it difficult to detect MNi automatically by an imaging algorithm. b Fixation by the hypotonic process established in this study. Cells were fixed with hypotonic 1% PFA in 0.075 mol/L KCl (PFA/KCl). The swollen cells spread across the bottom of the well during dehydration. The separation of MNi from the primary nuclei made it easy to detect MNi automatically

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