Typhon and Spotiton: Multiplexed TEM Sample Preparation

Jeff Speir, Selected Poster Presentation
Gordon Research Conference – Three Dimensional Electron Microscopy
June 22-27, 2014
Melia Golf Vichy Catalan Business and Convention Center
Girona, Spain

The talk detailed two systems we are developing to overcome limitations of the current standard sample preparation techniques used in negative stain EM and Cryo-TEM.  Traditional sample preparation methods are very low-throughput, waste sample and have poor reproducibility in producing a grid with a uniform surface area suitable for imaging.  The need to prepare and screen multiple grids in the microscope for a single sample leads to high operational costs in both time and resources.  Both systems under development use piezo-electric inkjet print heads controlled by automated robotics to precisely dispense picolitre volumes, which enables the placement of multiple samples on a single grid for imaging.  Combined with the Leginon software system, high throughput imaging of all samples on the grid at multiple scales is obtained in a semi-automated processes, starting with an overall atlas of the entire grid. Intermediate magnification images are then used to target within each spot and the user defines the number of high magnification images they wish to acquire for each sample spot.  We have demonstrated the feasibility of both prototype systems to place multiple samples onto a single TEM grid.  We are continuing to optimize both the grid preparation as well as the automated TEM data collection strategies and expect that the systems will significantly increase the throughput and lower the cost for using TEM in structural biology.