CryoEM Services for Protein Structure Determination
Understand the interplay between structure and function for your high-value drug target via our dedicated, end-to-end cryoEM workflow – and access specialist expertise to get the most out of your project.
Reduce the cost and time investment required to move your drug molecule to the clinic
- The protein construct is hard to crystallize
- The target is conformationally dynamic
- You have a large biomolecular complex
- You work with membrane or membrane-associated proteins
- A high- resolution map of an epitope is needed
Connect with the first and largest CRO to own and operate the necessary tools for full structure enablement
Our cryoEM workflow: From initial sample to 3D reconstruction, model building and refinement
Negative Stain Screening
The first step in the workflow is a cursory examination to determine whether the sample is sufficiently pure and homogeneous for further, more detailed study by electron microscopy. At this stage, the sample should show evidence of well-defined, separated, high contrast particles of the expected size, with minimal or no aggregation. We have a long-standing expertise in the field, and we will work with the client to identify possible issues and provide suggestions on how to improve the sample.
Negative stain with 2D classification
Once the sample has shown no or minimal aggregation, a detailed negative stain analysis performed to verify that the overall size, structure, oligomerization state, domain organization and conformational heterogeneity of the particles are consistent with those expected for the macromolecule of interest. Sample grid preparation at this stage is carefully optimized to maximize the quality and resolution of the images with sufficient data acquired to perform 2D class averaging. Several of the resulting class averages must be clearly interpretable, with crisp features, limited disorder and flexibility, and limited oligomerization states to be prioritized for subsequent cryoEM study.
CryoEM grid preparation and screening
Grid prioritization & low-resolution data acquisition
Screening of the grids with the Glacios microscope is used to identify the presence (or absence) of these potential issues that might prevent the client from obtaining high resolution structures. Grids are prioritized to maximize the likelihood that a structure of suitably high resolution can be achieve from data acquired on the Titan Krios instrument. Grid screening can be combined with acquisition of an overnice dataset on the Glacios, which is subsequently used to obtain 2D classes (and sometimes a 3D reconstruction) to assess sample quality.
Data acquisition on in-house Krios microscopes
Data processing & 3D reconstruction
NIS offers a complete workflow for data processing that leads to a 3D reconstruction. This workflow includes particle picking, 2D classification, 3D classification, and 3D reconstruction. The many particles present in the images are initially classified into 2D classes. Each class provides a different projection view of the macromolecule of interest, and these views can be mathematically combined to generate a 3D map. The reconstructed map provides information for the entire volume of the particle, both surface features and internal morphology, and can reach atomic-level resolution.
Fast, Flexible, Customized Services
In addition to project-based proposals, NIS offers custom service packages allowing you to get the most out of your specific program.
Training & Instrument Access
Our service offering combines a CRO approach with training and instrument access typically only accessible via academic and national laboratories.
Data Acquisition-Only Packages
As well as onsite training in sample preparation and data acquisition, we also offer data acquisition-only programs for users.
- These are both available for general user access and allow our customers to generate thousands of images daily
- More than 70% of structures determined from Krios-generated data achieve resolutions better than 3.5A
- Installed across our locations to allow for local sample screening, preparation and analysis
- A high-speed network will connect our facilities and the Krios microscopes for high-resolution data acquisition
- Integral membrane proteins (including ion channels, transporters, and GPCRs)
- Large protein complexes
- Molecular machines & dynamic systems
- Gene editors
Learn more about the different ways you can work with us through our Working With Us resource.
Request a CryoEM Consultation
Speak with a member of our scientific team about feasibility and sample considerations.