Abstract
Growth of magnetosomes in magnetotactic bacteria is important in the biological sciences and application of medical biomimetic materials, such as gene therapy and cancer heat treatment. However, the growth mechanism is still inconclusive so far. Traditionally, magnetotactic bacteria and magnetosomes have previously been studied by cryo thin sections method, which is difficult to directly observe the synthesis process. In this study, we aim to observe the process of magnetosome synthesis, and according to this purpose to design a series of experiments, including (1) Application of MEMS process design on Flow cell development and (2) Application of Hollow cone dark field (HCDF) on photographing objects in liquid environment in TEM. In Flow cell, we use (1) metal deposition, or (2) photoresist coating method to design different thickness spacers to control the thickness of the liquid and space. With combination of Flow cell and liquid holder, we can provide an open system for bacteria. In order to solve the weak contrast of biological samples (arising from low atomic number elements of sample), we use tilt illumination hollow cone dark field by adjusting two lens system to shift the incident electron from the central axis to increase the image contrast.