Cryo-transmission electron microscopy

Knowledge graph centered on Cryo-transmission electron microscopy with 17 nodes and 34 connections. Top connected: Bacteria, biogeochemical cycling, Structure and composition of natural ferrihydrite , iron speciation, EXAFS spectroscopy.

Method synopsis

Cryo-TEM analysis of colloidal particles involving vitrification of samples on holey carbon grids followed by high-resolution imaging at cryogenic temperatures to preserve native morphology.

Synthesized from method descriptions across 1 paper using this protocol.

Procedure from a recent peer-reviewed implementation

Steps below were extracted from the most recent peer-reviewed implementation of this protocol in the corpus — Structure and composition of natural ferrihydrite nano-colloids in anoxic groundwater (2023), Water Research. Implementations in other papers (listed below) may differ.

1. Prepare samples for microscopy
   Porewater solution (130 or 180 cm depth; 0.22, 0.1, and 0.02 μm; sampled in May and June 2021) was blotted (3 μL) onto a Quantifoil holey carbon TEM grid (C-F 1.2/1 with 2 nm carbon film) and immediately plunged into liquid ethane using a Thermo fisher Vitrobot. The frozen grids were maintained under liquid nitrogen until transfer to the cryo-TEM
   Quantities: 3 μL sample volume per gridDuration: Immediate processing after samplingConditions: Cryogenic conditions for preservation
   Equipment: Quantifoil holey carbon TEM grids, Thermo Fisher Vitrobot, liquid ethane, liquid nitrogen
2. Perform cryo-TEM analysis
   Experiments were performed on a Thermo Fisher Titan Krios G3 TEM operated at 300 kV located at the Stanford-SLAC Cryo-EM center. Cryo-TEM images were acquired by a K3 direct-detection camera in energy filtered electron-counting mode with magnification of 205,000 with a pixel size of 0.41 Å by 0.41 Å and electron dose rate of 45 e−/Å2/s per image. The exposure time was 2s per image with 0.1s per frame, resulting in 20 frames per image
   Quantities: Magnification of 205,000x, pixel size 0.41 Å, dose rate 45 e−/Å2/s, 2s exposure, 0.1s per frame, 20 frames per imageDuration: 2s exposure time per imageConditions: 300 kV electron beam, cryogenic temperatures
   Equipment: Thermo Fisher Titan Krios G3 TEM, K3 direct-detection camera

Typical Equipment

• Quantifoil holey carbon TEM grids
• Thermo Fisher Vitrobot
• Thermo Fisher Titan Krios G3 TEM
• K3 direct-detection camera

Output Measurements

• particle morphology
• size distributions
• structural preservation

Papers Using This Protocol (1)

Species Studied With This Protocol