Imaging of fine structures of cellular organelles in hydrated biological cells by a soft X-ray microscope combined with a fluorescence microscope

Kado, Masataka; Kishimoto, Maki; Tamotsu, Satoshi*; Yasuda, Keiko*; Aoyama, Masato*; Shinohara, Kunio*

We have proposed to use a fluorescence microscope to identify the cellular organelles in the images obtained with the soft X-ray microscope observing the same cells with both microscopes. The cells were stained with several fluorescent dyes such as Mito-tracker, Phalloidin, and DAPI and after taking many fluorescence images of cellular organelles the cells were exposed to the flash soft X-rays. The obtained soft X-ray images and fluorescence images of the cells were directly compared and each of the cellular organelles such as mitochondria, actin filaments, and chromosomes in the soft X-ray images was clearly identified. Since the soft X-ray microscope has higher spatial resolution than that of the fluorescence microscope, fine structures of the cellular organelles in the hydrated biological cells were observed for the first time.