동결 수화된 생체 시료에 대한 결맞은 엑스선 회절 현미경의 개발

Abstract

Coherent X-ray di ffraction imaging(CDI) is the technique to determine the electron density of the sample by measuring the di ffraction pattern from coherent X-ray directly incident to the sample without any optical component. Without the other optics, experimental setup is simple and there is no limit of determination due to it. So, this technique is extremely effi cient to determine the broad range of nanoscale structures. However, for biological specimens, the intense incident photons occur radiation damage which is obstacle for high resolution imaging. In this thesis, cryo coherent di ffractive imaging is introduced to overcome this problem. The target sample is cyanobacteria, which not only has importance as producer of environment but also the possibility to become a new energy source as biofuel. By exposing biological sample to low temperature helium gas flow, radiation damage by incident beam is eff ectively relieved. The di ffraction patterns of 􀀀30 , 0 , 30 are obtained. The high resolution images for 3 angles are reconstructed by GHIO algorithm. These images show the inner structure of cyanobacteria such as carboxysome and thylakoid. This work gives us the deeper biological understanding of cyanobacteria and pave a way to conduct high resolution 3D imaging in the future.