Nano Argovia projects – Function test before flash-freezing

In the Nano Argovia project FuncEM, researchers are developing an extension of the cryoWriter system, which can be used to flash-freeze tiny quantities of samples — with no loss of material — before they are examined using cryo-electron microscopy. The aim is for the planned extension module to allow “living” samples to be imaged under an optical microscope immediately prior to the freezing process. This will allow researchers to obtain important information about the functionality of the analyzed structures.

Nicolas Candia and Alejandro Lorca Mouliaà of cryoWrite are working with the Nano Argovia project team to further develop cryoWrite technology. (Image: cryoWrite)

Preparation of tiny sample quantities
It’s hard to imagine modern biomedical and basic research without cryo-electron microscopy (cryo-EM), a technique that allows detailed three-dimensional imaging of tiny structures in biological samples.

The young start-up cryoWrite AG has developed a sample preparation system that can be used to instantly cool tiny quantities of sample materials down to temperatures below -150°C with no loss of material. In the process, the water contained within the sample does not form crystals but rather adopts a glass-like state in a process known as vitrification. As this process leaves the molecules in the cells intact, cryo-EM can then be used to examine them very closely and visualize their three-dimensional structure.

Correlation between structure and function
In many situations, it would be useful for researchers to be able to examine the functionality of target structures in living samples immediately prior to vitrification with a view to analyzing correlations between structure and function.

As part of the Nano Argovia project FuncEM, researchers from the University of Basel, the Paul Scherrer Institute PSI and the company cryoWrite are therefore developing and testing an extension module for the cryoWriter system that allows the thin sample layer to be imaged using fluorescence and dark-field microscopy immediately prior to vitrification.

Under the leadership of Dr. Thomas Braun from the Biozentrum, this interdisciplinary team is initially focused on examining thin organelles known as cilia. These threadlike projections play an important role in the movement of eukaryotic cells and in numerous diseases.

The researchers are carrying out their analyses using a newly developed prototype of the cryoWriter system, which allows the sample to be examined directly on the sample holder using optical and fluorescence microscopy.

In this process, the sample environment ensures cell survival and does not restrict the motility of the cilia. The team is also planning to set up a monitoring system to record the movements of these organelles. As these examinations will take place on the same sample holder immediately prior to sample vitrification, they will allow researchers to establish a direct link between functionality and the identified structure.

“The Nano Argovia program is a fantastic opportunity for us to refine our new prototype in collaboration with specialists from the Biozentrum and the Paul Scherrer Institute, thereby improving our opportunities in the marketplace.”

Professor Andreas Engel, CEO at cryoWrite AG

Further information:

Nano Argovia program

cryoWrite AG

Research group Thomas Braun

Paul Scherrer Institute