Automated Tools For Electron Microscopy
The dramatic improvements in the progress of cryo electron microscopy (cryoEM) over the last five years has been accompanied by the adoption of a high level of automation. However, there are several automation challenges that remain to be addressed in the areas of specimen preparation, image acquisition, and analysis. In specimen preparation we need to address methods to ensure routine and robust preparation of particles embedded in a thin layer of vitreous ice. Our own group has developed a system that uses nanoliter droplets dispensed onto a self wicking grid that provides for a uniform and
thin layer of vitreous ice and improves the efficiency of data collection. More importantly it also appears to ameliorate adverse effects caused by proteins interacting at the airwater interface. In the area of image acquisition we anticipate a 10 fold increase in throughput assisted by a new generation of direct detectors. Additional instrument advances that would improve data throughput include developing faster and more stable cryo stages and further automating some of the steps required for high resolution imaging. Finally in the area of image analysis, the software continues to rapidly improve both in terms of speed and in being able to sort out highly heterogeneous populations of molecular complexes. All of these advances are being driven by the urgent needs of structural biologists and increasingly by the needs of pharmaceutical and biotechnology companies. The latter group in particular is driving the need for much higher levels of automation and much higher throughput.