Quantitative determination of beam irradiation damages to biological specimens caused by STEM tomography
Abstract: Until now, Scanning transmission electron microscopy (STEM) tomography has not yet become popular in the biological research field. It is widely considered that the beam damage of STEM would be very severe, since a convergent electron beam is required for the imaging. On the other hand, STEM allows us taking tilt series of images from thick biological specimens (up to 1μm) without using ultra-high voltage electron microscopy for finding out 3-D reconstruction of the specimens. To demonstrate a benefit of STEM tomography for the analysis of biological specimens, the shrinkage of the specimens was measured for the quantification of the beam irradiation-induced damage. The difference of the size of intracellular organelles, such as mitochondria was determined, before and after taking the tilt series of images for tomography. In the result, it was appeared that the beam irradiation-induce damage of STEM tomography was considerably less than that of TEM tomography.
Key words: STEM, TEM, electron tomography, irradiation-induced damage, resin-embedded