CERES: Powerful tools for minimizing ice contamination
The CERES Ice Defense System is a platform designed to minimize ice contamination during Cryo-ET and Cryo-EM workflows. Comprised of three modular tools: the Ice Shield, Clean Station, and Vitri-Lock, the system functions in harmony to minimize ice contamination at every step in the sample preparation workflow. With CERES, researchers can experience an unprecedented high sample yield, leading to powerful insights faster.
- Minimize ice contamination at every step of the workflow – preparation, transfer, and milling.
- Obtain better quality cryo-EM and cryo-ET results, higher throughput, and higher resolution.
- Save valuable time and resources by bringing only high-quality samples to the cryo-TEM.
Three Components to Reduce Ice Contamination
Provides a clean and moisture-free platform for cryo-EM users to prepare samples with ease.
Ensures seamless and contamination-free transfer for up to 30 minutes.
Offers the ultimate protection against ice contamination during lamella milling using our patented technology.
Watch a short video overview
The Real Impact of ice contamination
In a recent survey conducted by Delmic, over 80 cryo-EM users were asked about how ice contamination impacts their workflows1
The results showed that ice contamination is a profound issue affecting a significant amount of cyro-EM microscopists. Not only is the quality of TEM data reduced due to ice contamination, but many samples are rendered useless.
CERES was created to effectively contain the many sources of ice contamination in cryo-ET workflows and ultimately gives users confidence and peace of mind that their delicate samples will produce high-quality data.
1. K. Lau, C. Jonker, J. Liu, M. Smeets. “The Undesirable Effects and Impacts of Ice Contamination Experienced in the Cryo-Electron Tomography Workflow and Available Solutions.” Microscopy Today 2022, 30, 30-35.
How Does Ice Contamination Impact Your Research
The CERES workflow
Step 1 Import your sample
Begin by importing your sample to the Clean Station through the dedicated airlock. Using the touchscreen interface, initiate the vacuum pump down and replacement with nitrogen gas. Once the airlock contains <1 ppm of moisture, samples can be transferred via the interior door of the airlock.
Step 2 Manipulate your sample
The Clean Station accepts a wide variety of glove types and thicknesses and is fitted with an articulating LED magnification arm to provide the user maximum flexibility. Use the preparation station to manipulate, mount, transfer, and clip delicate samples. Confidently keep samples in a vitrified state as they are bathed in liquid nitrogen.
Step 3 Export Sample to FIB/SEM
With the samples loaded into the shuttle, use the Vitri-Lock to retrieve the sample and transfer it to the FIB/SEM. The interior chamber of the Vitri-Lock is cooled via an on-board liquid nitrogen battery to protect your sample from devitrification.
Step 4 Lamella milling
Next, perform guided lamella milling in the FIB/SEM with the integrated cryo-CLEM device, METEOR. Ensure ice contamination is minimized during milling with Ice Shield. Together, METEOR and Ice Shield boost sample yield and productivity leading to high quality samples.
Step 5 Re-import Lamella for cassette loading
After milling is complete, use Vitri-Lock again to transfer samples from the FIB/SEM back to the Clean Station. Next, transfer delicate samples from the shuttle into an autoloader cassette using the cassette loading module. The loaded cassette can then be moved to a TEM cassette loading zone with supplies to accept commonly available transfer devices from ThermoFisher such as the Nanocab.
Step 6 Transport sample to the TEM
With the Nanocab (or other transfer device) loaded and ready for transport to the TEM, simply open the load lock interior door and use the sliding metal table to reposition the samples. The interior door will then be closed, and the exterior door opened allowing for final transport to the TEM.
Ice Shield for Frost-Free Samples
Did you know that the typical 50 nm/min ice growth rate accepted by cryo-FIB providers would mean your 150-nm lamella could become several times thicker at the end of your sample preparation session?
This ultimately impacts the quality of data and in more extreme cases means the targeted structure is completely obscured.
The Ice Shield is a highly engineered and patented shutter designed to minimize ice contamination originating from the electron column during milling. Precision machined with a hole to allow for FIB milling while in place, the shutter automatically retracts when in SEM mode for quick inspections. Real results from before and after installation show that the ice growth rate was effectively reduced to zero.
Clean Station + Vitri-Lock: Making dry rooms obsolete
The CERES Clean Station is tailored for cryo-EM sample preparation. Together with Vitri-Lock, this powerful combination boasts many features that make the platform highly effective against ice contamination, making them more effective than traditional dry rooms.
Vitri-lock: Safe transfer for up to 30 minutes
Unlike the current commercially available solutions that rely on a low/mid-vacuum environment, CERES Vitri-Lock maintains transfer times up to 30 minutes by employing a high-vacuum, anhydrous environment. The chamber is actively cooled by an exterior liquid nitrogen reservoir, keeping the sample below -150°C while maintaining a high vacuum environment through cryo-pumping.
The prolonged ‘cold time’ enables users of Vitri-Lock to keep their samples vitrified and contamination-free even during the lengthy sample screening step. When used together with the CERES Clean Station, users can confidently and seamlessly transfer samples throughout their workflow.