Minimizing ice contamination at every step of cryo-EM workflow

Delmic Press Release April 15, 2021

Following the innovative cryogenic electron microscopy (cryo-EM) solution METEOR, we are delighted to launch a new cryo-EM solution, CERES Ice Defence System, a series of powerful tools that will minimize ice contamination at every step of your cryo-EM workflow: preparation, transfer and lamella generation.

From the survey results we collected, ice contamination during lamellae preparation affects almost every researcher to a certain extent. On average over 30% of the lamellae used for tomogram acquisition have more than 50% unusable area and nearly half of our respondents realize the samples are ice contaminated already at the transmission electron microscope. Such hassles not only bring frustration but also can cause a drop in productivity. Helping the worldwide researchers have a happier research life has always been Delmic’s mission. Therefore, in collaboration of Max Planck Institute for Molecular Physiology in Germany, we developed CERES Ice Defence System, which consists of CERES Clean Station, CERES Vitri-Lock and CERES Ice Shield. These three innovative tools will give maximum protection to your cryogenic samples so that you can obtain the highest quality cryo-EM samples, with higher throughput and world-class results.

CERES Clean Station

During the cryo-EM sample preparation, it’s very common that parasitic ice crystals from contaminated liquid nitrogen to grow on the sample. Hence, you need a low-humidity and space-saving sample preparation environment to secure your cryo lamellae. CERES Clean Station is the perfect tool as it provides a less than 1% humidity/100 ppm water environment, which promises you with no more effort wasted preparing precious samples only to get it ice contaminated. Thanks to the user-friendly gloves design, you can also expect a high agility while handling the fragile samples.

CERES Vitri-Lock

From the survey results, half of researchers think the ice contamination during sample transfers bothers them the more than other issues. CERES Vitri-Lock, a high vacuum cryo transfer (HVCT), ensures that cryogenic samples stay vitrified during all the cryo sample transfers, in between the preparation station, fluorescent light microscope (FLM), scanning electron microscope (SEM)/FIB and TEM. Additionally, ‘cold time’ is also prolonged up to 30 minutes so that transferring samples between stations won’t require you running anymore.

CERES Ice Shield

The survey results also showed that 13% of researchers expressed their struggles with ice growth during sample thinning, which definitely held them back from an automated milling process. As certain ice contamination rates are currently admitted by major cryo FIB/SEM suppliers, SEM users are forced to experience time pressure during the milling process. Our patented innovation, CERES Ice Shield, was therefore created to give ultimate protection to the sample within the FIB /SEM chamber. By providing a colder surface within close proximity to the cryo sample and preventing any residual moisture in the chamber to condense on the sample, CERES Ice Shield enables you to take your time during sample milling and even leave lamellae in the cryo-FIB/SEM overnight without any contamination concerns.

Working with CERES Ice Defence System (For FIB/SEM)

Load plunge frozen samples into Clean Station via the antechamber, perform C-clipping and sample-shuttle assembly on the LN2 cooled preparation table in the chamber, pump Vitri-Lock chamber to high vacuum and then load the sample-shuttle into Vitri-Lock for transfer to the cryo-FIB/SEM for lamellae preparation. When the lamellae samples are prepared, transfer the samples to Clean Station from the cryo FIB/SEM using Vitri-Lock. Use the cassette loading module on the preparation station in Clean Station to load samples with lamellae into the cassette for the downstream cryo-TEM process.

DeCERES Ice Defence System is user-friendly solution in the market, that secures your cryogenic samples to the maximum. Without ice contamination challenge, you can concentrate on acquiring more data to understand the building blocks of life with ease. Visit our website to learn about how CERES Ice Defence System can boost your productivity: https://www.delmic.com/en/products/cryo-solutions/ceres-ice-defence-system