Measurement of ice thickness and quality to optimise and qualify robotic cryo-plunger

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**Automatic cryogenic electron microscopy (cryo-EM) sample preparation system from Linkam to tackle inconsistency and bottlenecks in cryo-EM workflow**The development of cryo-EM has made high resolution structural information of proteins and cellular components available to researchers in biological studies and drug discovery. A Nobel prize for cryo-EM was awarded in 2017 ([https://www.nobelprize.org/prizes/chemistry/2017/press-release/][0]).Conventional cryo-EM relies on the rapid freezing of samples (protein particles or cellular components) in vitrified ice to preserve structures down to molecular level. This can be achieved by plunge-freezing, however, the typical machines and processes used for the plunge freezing are mostly manual and use conventional blotting paper. This substantial user-dependent process always lead to poor consistency, and is considered as a bottleneck of the overall cryo-EM workflow.The novel design of the Linkam CryoGenium robotic sample preparation system has optimised the sample freezing process of cryo-EM using a Linkam - patented design for the adjustment of the sample film thickness automatically. CryoGenium provides a single platform for controlled cryogenic conditions and eliminates any undesirable user-dependent effects during the sample preparation process.This current A4i project intends to perform a structured investigation of vitrified sample (ice) quality using a defined set of samples. The ice thickness is determined by energy filter measurements and a built-in cryo-EM imaging system. The set of quantitative measurements will give better insights into the relationship between instrument settings and the quality of sample results. Further system optimisation based on statistical parameters will be achieved to further improve repeatability and sample uniformity compared to conventional sample freezing methods. A secondary goal of the project is to enhance the user-friendliness of the instrument and software with feedback from this extended trial.Overall this new device can help to further establish cryo-EM as a routine tool to study cellular and molecular structures with implications for the understanding disease mechanisms and the design of drugs.[0]: https://www.nobelprize.org/prizes/chemistry/2017/press-release/