Cryo-electron Microscopy (cryo-EM) Technology

Cryo-electron microscopy (Cryo-EM) is a powerful analysis tool for studying protein/peptide crystal structures, including atomic distribution, crystal degree, grain size, and defect. With decades of rich experience in developing and performing cryo-EM analytical methods, CD Formulation uses cryo-EM technology to provide reliable analytical support for the development and characterization of your protein/peptide drugs, from early development to late product release testing.

What is Cryo-electron Microscopy (cryo-EM) Technology?

Cryo-EM is a powerful imaging technology that is used to determine the 3D structure of proteins and peptides with high resolution. This technology involves freezing the sample in a thin layer of glass ice to retain its natural structure and prevent the electron beam from damaging. Unlike traditional X-ray crystals, cryo-EM is a new technology that does not require crystallization. In the cryo-EM analysis, cryo-EM samples can maintain a low temperature of 24-72 hours in frozen electron microscopes, so that researchers can collect all the data they need to reconstruct three-dimensional reconstruction as high as possible.

Cryo-electron Microscopy (cryo-EM) Principle

The principle of cryo-electron microscopy is to freeze the sample in a thin layer of vitreous ice. This maintains structural integrity and minimizes radiation damage compared to traditional electron microscopy techniques. In cryo-electron microscopy, purified protein and peptide samples are applied to a thin grid, which is then immersed in a cryogen (usually liquid nitrogen) to quickly freeze the sample. The frozen sample is then transferred to an electron microscope, where it is bombarded with an electron beam. The electrons interact with the sample, producing an image that is recorded by the detector. The advantage of this technique is that the low temperature of the sample reduces the movement of molecules, allowing high-resolution imaging of biological structures. In addition, the use of vitreous ice to quickly cool the sample to a low temperature prevents the crystallization of water molecules in the sample, providing a more natural environment for the sample, and preserving its natural state.

Fig. 1 Cryo-electron microscopy (cryo-EM) work flow.(Shen PS, et al., 2017)

Our Services Related to Cryo-electron Microscopy (cryo-EM)

Thanks to decades of experience in supporting protein/peptide biopharmaceutical development and manufacturing using cryo-EM technology, our team of highly qualified experts offers a range of cryo-EM-related services to accelerate the implementation and success of your projects.

Our experienced team of experts has completed hundreds of protein and peptide cryo-EM analysis projects, allowing support for all stages of your protein/peptide drug development and manufacturing - from early studies to downstream process monitoring and GMP batch release testing.

Utilizing cutting-edge cryo-EM technology, we support the following protein/peptide characterization plans, including but not limited to:

Protein and Peptide Drug Discovery

Cryo-EM plays an important role in drug discovery and development by elucidating the structure of drug targets. Our scientists use this technology to accelerate your protein and peptide drug discovery programs by rationally designing drugs, understanding ligand binding mechanisms, and optimizing drug efficacy and specificity.

Protein and Peptide Crystal Structure Elucidation

Crystal structure is an intrinsic feature that determines the physicochemical properties of proteins and peptides. Our structural biology experts frequently use this technique to solve the structures of large proteins, such as the membrane-bound proteins that constitute the targets of most modern drugs, as a complement to X-ray crystallography. If your protein is smaller than 80 kDa or contains more than 700 amino acids, X-ray crystallography will be used.

Nanoparticle Structural Characterization

Nano-delivery is a powerful tool for protein and peptide drug delivery. Our scientists use cryo-EM (usually cryogenic scanning electron microscopy) to accurately study the morphology, surface structure, and crystal structure of nanoparticles to gain a deep understanding of the properties and behavior of nanomaterials, thereby optimizing their design and improving their performance to achieve more efficient protein and peptide drug delivery.

Our Workflow for Cryo-electron Microscopy (cryo-EM) Analysis

• Sample Preparation: usually purified proteins or complexes in solution.
• Freezing: The sample is quickly frozen by placing it in a cryogenic fluid (e.g. liquid ethane), causing the sample to vitrify and retain the native structure of the protein.
• Cryo-EM: The vitrified sample is transferred to a cryogenic electron microscope. The microscope is calibrated and aligned, and then data acquisition begins. The electron beam is aimed at the sample, producing a series of 2D projection images from different angles.
• 2D Projections: These 2D images are processed to correct artifacts and improve the signal-to-noise ratio.
• Pick Particles, Alignment, and Averaging: Particle picking identifies individual particles in the image and collects large particle data sets.
• Algorithmic Analysis: 3D density maps are reconstructed from particle images.

Fig. 2 Workflow for protein/peptide structure determination using cryo-EM. (CD Formulation)

Available Types of Cryo-electron Microscopy (cryo-EM) Analysis

The most typical feature of cryo-EM is the use of cryogenic fluids to vitrify samples, which can be used as a variant of conventional electron microscopy techniques. Our analytical laboratory is equipped with the following two types cryo-EM to help you solve any possible structural challenges.

Cryogenic Transmission Electron Microscopy (cryo-TEM)

In this technique, a vitrified sample is loaded into a high-vacuum TEM instrument. As the electron beam passes through the sample, it interacts with the electrons, causing scattering and absorption. This interaction results in a projected image on the detector, which captures the two-dimensional structural information of the sample. Based on this, multiple projected images are collected by tilting the sample at different angles within the microscope. They are then processed using advanced computational algorithms to generate a three-dimensional density map of the sample.

Cryogenic Scanning Electron Microscopy (Cryo-SEM)

This technique is used to study the surface structure and morphology of a sample. The vitrified sample is usually broken to expose its internal surface, which is then transferred to the SEM instrument. When the electron beam interacts with the sample, secondary and backscattered electrons are emitted, which are then detected and used to create an image of the sample surface.

Advantages of Our Cryo-electron Microscopy (cryo-EM) Technology

• An alternative method that can obtain structure without forming a crystal, which is more suitable for a wider range of proteins and complexes (compared with X-ray crystal).
• More applicable to study larger and more complicated structures, such as large and flexible complexes, as a supplement to NMR technology.
• High-precision, near-atom resolution imaging.
• Single particle analysis is not subject to size restrictions.

Custom Cryo-electron Microscopy (cryo-EM) Services

Why Choose Our Cryo-electron Microscopy (cryo-EM) Technology?

• We have an expert team of structural biology, protein science, and pharmaceutical scientists who can provide one-stop services for your protein or peptide product, from crystal structure analysis for drug discovery to crystal structure analysis for process development and cGMP manufacturing.
• Our facilities are equipped with state-of-the-art cryo-EM instruments for high-resolution imaging and analysis of protein and peptide samples in their native state.
• From sample preparation and data acquisition to analysis and interpretation, we provide comprehensive support at every stage of the cryo-EM process, helping you meet challenges and achieve your research goals.
• We utilize the latest software tools for image processing and structural analysis, providing you with high-quality data and comprehensive analytical capabilities.
• We value our partnership with our customers and are committed to providing continuous support and guidance during the project to ensure that your plan is implemented smoothly.
• We offer flexible experimental design and testing options to meet the specific needs of any customer.
• Fast turnaround time: comprehensive reports are provided within 1 to 4 weeks depending on sample size and services selected.

Publication

CD Formulation aims to provide a powerful analytical tool for protein and peptide crystal structure elucidation. Please feel free to contact us if you are interested in our services. Learn how our cryo-EM technology can support the smooth implementation of your protein/peptide biopharmaceutical program.

How It Works

STEP 1

Submit a service request describing your specific research or development need.

STEP 2

We'll email you to provide your quote and confirm order details if applicable.

STEP 3

Execute the project with real-time communication, and deliver the final report promptly.