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Single Particle Cryo-Electron Microscopy: From Sample to Structure
Published on: May 29, 2021
Improvements to a cryosystem to observe ice nucleating in a variable pressure scanning electron microscope
D Waller1, D J Stokes, A M Donald
1Biological and Soft Systems, Cavendish Laboratory, Department of Physics, Cambridge University, Cambridge CB3 0HE, United Kingdom.
The Review of Scientific Instruments
|December 3, 2008
Summary
Variable pressure scanning electron microscopy (VPSEM) now images dynamic, hydrated samples. A new cryosystem enables in situ ice nucleation observation at low temperatures, expanding VPSEM capabilities.
Area of Science:
- Materials Science
- Microscopy
- Physical Chemistry
Background:
- Variable pressure scanning electron microscopy (VPSEM) enables imaging of hydrated and insulating samples using water vapor.
- There is increasing demand to study dynamic hydrated samples at temperatures beyond the usual room temperature range in VPSEM.
- Existing VPSEM systems have limitations in controlling sample temperature for studying phenomena like ice nucleation.
Purpose of the Study:
- To develop a cryosystem for VPSEM to enable in situ observation of hydrated samples at low temperatures.
- To investigate the nucleation of ice from a solution within the VPSEM.
- To explore the imaging of hydrated samples in the temperature range of 188-238 K (-85 to -35 °C).
Main Methods:
- Development and integration of a cryosystem into a VPSEM.
- In situ observation of ice nucleation from a solution.
- Systematic study of internal surface temperatures and their effect on sample hydration.
- Imaging hydrated samples at temperatures between 188-238 K.
Main Results:
- Successful development of a cryosystem for VPSEM, allowing for low-temperature imaging.
- Direct observation of ice nucleation from a solution in situ.
- Demonstration of the capability to image hydrated samples in the 188-238 K temperature range.
- Understanding the influence of internal microscope temperatures on sample hydration states.
Conclusions:
- The developed cryosystem significantly expands VPSEM capabilities for studying hydrated samples at low temperatures.
- In situ ice nucleation can be successfully observed using this advanced VPSEM setup.
- The findings open new avenues for exploring hydrated sample dynamics in a previously underutilized temperature range.
- Precise temperature control is crucial for maintaining sample hydration and native states during low-temperature VPSEM analysis.
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