Selectris and Selectris X Imaging Filters

With the Selectris Filters, zero-loss energy filtering is straightforward due to the thorough integration of software and hardware along with extensive automation and exceptional stability. Every mechanical and electron-optical element has been designed for stability and data reproducibility, enabling the unattended and reliable acquisition of large datasets with narrow energy slit widths (<10 eV). The capability to use these narrow slit widths provides an additional boost in contrast for single particle cryo-electron microscopy (cryo-EM), enhancing signal strength, resolution, and throughput.

Paired with the latest generation Thermo Scientific Falcon 4i Direct Electron Detector, Selectris Filters allow you to obtain high-resolution structures quickly, revealing new biological insights. Incorporated Falcon 4i camera with electron event representation (EER) enables efficient file size compression, super-resolution capabilities and maximized sensitivity for all use cases. To further increase the productivity and ease-of-use of your cryo-EM workflows for single particle analysis and cryo-electron tomography, these filters are fully integrated into Thermo Scientific EPU Software, Thermo Scientific Tomography Software, and our instrument operation software.

How energy-filtering transmission electron microscopy works

Upon interacting with the sample, electrons may scatter elastically or inelastically. The Selectris Imaging Filter allows elastically scattered electrons to pass through, thereby enhancing image contrast. The intrinsic mechanism is that through removing the noise caused by inelastically scattered electrons, the signal-to-noise ratio (SNR) and the contrast is increased.

The capability to use a very stable narrow slit width (<10 eV) provides an additional boost in contrast for single particle cryo-electron microscopy (cryo-EM) and cryo-tomography (cryo-ET), also enhancing resolution and throughput.

For example, let’s compare reconstructions of proteasome 20S with the same amount of particles (see table). A narrower energy slit (i.e. lower energy) leads to higher resolution compared to a larger slit width (20 keV) and even more improved compared to unfiltered image. This is because the B-factor has been reduced meaning less particles are needed to obtain a certain resolution.

Additionally, a narrower energy slit width (10 eV) translates into a lesser number of particles needed to obtain equivalent resolution (370k) compared to using a wider energy slit (see figure and graph). As a result, with the Selectris X Imaging Filter, you can obtain results faster with less data or maximize your resolution efforts.

Getting to lower energy slit widths, such as 5 or 10 eV, requires a very stable filter to avoid interruptions for filter alignment.

“We’re impressed with the stability of both the hardware and the software.  Due to the enhanced performance and stability, all our COVID-19 work is now done on the Selectris X Imaging Filter.  We routinely collect 5 eV tomograms, which was previously impossible.”

Alistair Siebert, Principal Electron Microscopist for the electron Bio-Imaging Centre (eBIC), Diamond Light Source

"The Selectris X Imaging Filter is clearly favored by us due to its stability and robustness, particularly when it comes to data collection for cryo-EM and cryo-ET that is carried out over extended periods of time. Once tuned, the filter is stable for over a month. The zero loss peak only moves by 1 eV over a week or even two!”

Dr. Juergen Plitzko, Max Planck Institute for Biochemistry, Martinsried Germany

See more of what's possible on the Glacios Cryo-TEM with Selectris X Imaging Filters ›

See more of what's possible on the Krios Cryo-TEM with Selectris X Imaging Filters ›

Designed for stability

• Narrow (<10 eV) zero-loss energy filtering offers enhanced contrast for higher resolution reconstructions
• Sophisticated aberration correction, low image distortions, and uniform energy resolution over entire field of view
• Minimized sensitivity to temperature variations

Straightforward operation

• Fully integrated with Thermo Scientific instrument operation software, as well as EPU Software and Tomography Software for data collection.
• Automated filter tuning completed in minutes
• No need to interrupt data collection for zero-loss centering

Falcon 4i Direct Electron Detector

• Unsurpassed image quality through higher DQE
• Large pixels with high signal-to-noise ratio (SNR)
• Higher throughput for more images per hour
• Lossless data compression with electron event representation (EER)

Fast, infrequent tuning

• Tuning can be completed automatically within minutes, on the rare occasion that filter tuning is necessary
• Experimental runs without interruption, for smooth daily operation and efficient data collection