VitroJet: Bridging the Gap in Sample Prep

Giulia Weissenberger, MSc
Application Engineer, CryoSol World
12:00 PM Tuesday, October 15

Through many exciting developments, cryo-electron microscopy (EM) has become a powerful method to elucidate 3D structures of macromolecular complexes. This knowledge provides valuable insight in understanding their functions and is the foundation for developing novel medicines. With the increasing demand of cryo-EM, sample preparation has become the major bottleneck that limits its true potential. Current commericial sample preparation techniques still rely on the methods established in the 1980’s that are limited in efficiency and reproducibility. Despite automated cryo TEM’s being common nowadays, plunge freezing with subsequent post clipping remains outdated. The VitroJet was developed introducing several controllable techniques and combines them into one device with minimal operator intervention. The device is a fully automated solution that functions with pre-clipped autogrids and is equipped with the functional components of sample preparation. Plasma cleaning of a grid is performed within the device prior to the deposition of sample through a novel blotless technique called pin printing. The layer quality is recorded for assessment as the grid is brought between two simultaneous cryogen jets for vitrification. This results in higher cooling rates and allows for vitrification of autogrids, removing the need to mount grids under cryogenic conditions. The VitroJet provides higher level of control in sample preparation, where grid quality can be evaluated without being bound to the microscope. The automated approach enables users to efficiently optimize sample conditions in the race to obtain new and exciting macromolecular structures.