3D visualization of subcellular structures of Schizosaccharomyces pombe by hard X‐ray tomography

Abstract

SummaryCellular structures of the fission yeast, Schizosaccharomyces pombe, were examined by using hard X-ray tomography. Since cells are nearly transparent to hard X-rays, Zernike phase contrast and heavy metal staining were introduced to improve image contrast. Through using such methods, images taken at 8 keV displayed sufficient contrast for observing cellular structures. The cell wall, the intracellular organelles and the entire structural organization of the whole cells were visualized in three-dimensional at a resolution better than 100 nm. Comparison between phase contrast and absorption contrast was also made, indicating the obvious advantage of phase contrast for cellular imaging at this energy. Our results demonstrate that hard X-ray tomography with Zernike phase contrast is suitable for cellular imaging. Its unique abilities make it have potential to become a useful tool for revealing structural information from cells, especially thick eukaryotic cells.

Imaging cell morphology and physiology using X-rays

“…In both categories of microscope soft and hard x-rays can be used, depending on the desired penetration depth, spatial resolution and contrast mechanism [54]. While there are multiple examples of using soft x-ray coherent diffraction imaging [55–61] and hard x-ray microscopy for visualizing cells [62–64] these techniques are mostly proof-of-principal studies and are not yet allowing the type of systematic studies required in cell biology. The preferred method for morphological studies of single cells is transmission soft x-ray microscopy.…”

Quantitative three-dimensional analysis of poly (lactic-co-glycolic acid) microsphere using hard X-ray nano-tomography revealed correlation between structural parameters and drug burst release

“…To improve the image contrast of BSA, the samples were stained with the heavy metals. In addition, nano-CT was operated in Zernike phase contrast mode [26]. A PLGA microsphere was picked up and glued on to the top of pin fixed on the sample holder.…”

“…In the present study, nano-CT was used to characterize the pore structure and drug distribution in PLGA microspheres encapsulating bovine serum albumin (BSA), fabricated by doubleemulsion solvent evaporation method, with sodium chloride added into the internal aqueous phase as an osmotic agent [26]. The results of nano-CT were compared with the traditional methods including SEM and CLSM.…”

Three-dimensional study of poly(lactic co-glycolic acid) micro-porous microspheres using hard X-ray nano-tomography

“…In order to improve the image contrast of BSA, the samples were stained with heavy metals. In addition, TXM was operated in Zernike phase contrast mode (Yang et al, 2010). Three PLGA microspheres prepared with different formulations were picked out and glued on the top of the pin, which was fixed on the sample holder.…”