The JEM-Z200FSC, or CRYO ARM™ 200 is a dedicated high-throughput cryoTEM. The CRYO ARM™ 200 can automatically acquire image data for Single Particle Analysis (SPA) which is crucial for high resolution data acquisition. The microscope has a cold field emission gun (Cold FEG) and an in-column energy filter (omega filter), capable of performing cryo tomography on frozen cell or tissue sections and whole small particles (e.g. bacteria, virus particles). The CRYO ARM™ 200 also incorporates software that automatically detects the relevant sample areas (‘holes’) on the specimen grid for high efficiency acquisition of SPA data.
In order to handle and process large cryo EM data sets, CAM installed a dedicated 8 NVIDIA A40 GPU server with 772 GB RAM, hosting RELION 3.1.3 and CryoSPARC 3.3.1, along with 177 TB storage space. RELION and CryoSPARC can also be accessed through the NCI (National Computational Infrastructure) supercomputer, Gadi (gpu-volta queue; NVIDIA V100 GPUs).
Since installation of the CRYO ARM™ 200, CAM staff have imaged and reconstructed the structure of the mouse Apoferritin complex. Using SerialEM data acquisition software, the team collected a dataset with 378 movies (4K by 4K) and processed it using CryoSPARC 3.3.1. By extracting a total of 107,155 particles from the dataset four 2D classes were obtained with 13,341 particles selected for 3D refinement. Ab-initio model building and final 3D refinement resulted in a 2.86 Å resolution structure of the complex.