Available systems: Two standard instruments
The Thermo Scientific Vitrobot Mark IV is a semi-automated plunge-freezing system used to vitrify liquid biological samples on electron microscopy grids.
A small volume of sample is deposited onto a grid inside an environmental chamber. Excess liquid is removed by programmable blotting, after which the grid is rapidly plunged into liquid ethane or another appropriate secondary cryogen.
The instrument allows important preparation parameters to be controlled, including:
- Chamber temperature
- Relative humidity
- Blotting time
- Blotting force
- Number of blotting cycles
- Waiting time before blotting
- Waiting time before plunging
- Grid position relative to the blotting pads
Main Applications
- Vitrification of purified proteins and macromolecular complexes
- Preparation of grids for single-particle cryo-EM
- Preparation of molecular cryo-ET specimens
- Vitrification of viruses and virus-like particles
- Vitrification of liposomes, vesicles, and nanoparticles
- Plunge freezing of small cells or bacteria grown on grids
- Optimization of ice thickness and particle distribution
The controlled temperature and humidity chamber helps reduce variability between grids and makes it possible to optimize preparation conditions systematically. Thermo Fisher Scientific describes the Vitrobot Mark IV as a semi-automated system that maintains controlled temperature, humidity, blotting, and freezing conditions for reproducible cryo-EM specimen vitrification.
Vitrobot Mark IV in an Anaerobic Glove Box
A dedicated Vitrobot Mark IV is installed inside an anaerobic glove box.
This configuration enables vitrification while limiting exposure to atmospheric oxygen and is intended for oxygen-sensitive or strictly anaerobic specimens.
Potential applications include:
- Oxygen-sensitive enzymes
- Redox-sensitive macromolecular complexes
- Anaerobic microorganisms
- Metalloproteins containing oxygen-sensitive cofactors
- Samples whose structure or activity changes rapidly following oxygen exposure
Sample preparation, transfer to the grid, blotting, and plunge freezing can therefore be performed in a controlled low-oxygen environment.
The compatibility of the buffer, sample container, cryogens, and transport procedure with the glove-box workflow should be discussed with platform staff before the experiment.