Unlocking the intricate 3D structures of biological macromolecules is fundamental to advancing life sciences and drug development. Among the powerful tools available for this, cryo-electron microscopy (cryo-EM) stands out, offering the ability to reveal high-resolution structures of complex biological systems in a state close to their native environment. For researchers seeking high-resolution structural analysis, navigating the complexities of Cryo-EM can be challenging. This handbook outlines the comprehensive cryo-EM services offered by Shuimu BioSciences, guiding you through their seamless "One-Stop" solution, from initial sample preparation to obtaining a detailed 3D structure.

Shuimu BioSciences, founded in 2017 at Tsinghua University, has rapidly established itself as a leader in structural biology services. Leveraging the deep research and technical heritage at Tsinghua University, Shuimu's EM Centre is led by a core team of world-class experts and is the first commercial platform in Asia offering cryo-EM structure determination. With a commitment to precision and efficiency, Shuimu provides advanced workflows for both experimental procedures and data analysis. Their mission is to provide "One-Stop" solutions for everything from gene sequences to high-resolution 3D structures.

To explore how Shuimu BioSciences can support your research with their cutting-edge cryo-EM services and achieve unparalleled high-resolution structural analysis, visit https://shuimubio.com/.

The Shuimu Advantage: A Platform Built for High Resolution

Achieving high-resolution structural analysis requires not just advanced instrumentation but also extensive expertise and refined workflows. Shuimu BioSciences boasts significant core strengths that underpin their ability to deliver top-tier cryo-EM services:

· Cutting-Edge Equipment: Shuimu operates the world’s largest commercial cryo-EM platform. They have eight 300 kV electron microscopes, with two located in Beijing and six in Hangzhou. These state-of-the-art instruments, equipped with high-performance detectors, energy filters, and phase plates, are purpose-built for high-resolution structural analysis and are maintained daily to ensure optimal performance. Each microscope maintains over 330 days of available machine time annually, with an annual fault-free operation rate greater than 97%. Shuimu also offers 24-hour instrument access for data acquisition.

· Elite Scientist Team: Their team is composed of PhD-level experts from preeminent institutions, specializing in structural biology, protein science, and computational biology. This experienced team oversees daily operations and maintenance, ensures professional operation during data collection, and provides real-time response to unexpected situations.

· Extensive Experience: Shuimu has completed over 400 cryo-EM projects. Their team has resolved structures covering a wide range of biological samples, including membrane proteins, antigen-antibody complexes, ion channels, GPCRs, spliceosomes, and small molecules.

· Uncompromising Pursuit of Resolution: Shuimu is dedicated to pushing the boundaries of resolution. They have resolved more than 150 structures, achieving a best resolution of 1.8 Å. They have also successfully elucidated protein structures as small as 51 kDa and achieved a groundbreaking resolution of 1.4 Å. For MicroED projects, they have delivered resolutions of 0.6~1.0Å.

· AI-Driven Platform: Shuimu has independently developed proprietary AI algorithms and software suites, such as the SMART software suite, NanoSMART, and eTasED. These tools significantly enhance efficiency and accuracy in cryo-EM data analysis, reduce machine runtime, and improve overall process efficiency. NanoSMART, for instance, automatically identifies nanoparticle features from images, providing detailed reports with one-click operation. eTasED integrates MicroED technology into conventional cryo-EM systems.

· Proprietary Technologies: Shuimu has developed a series of graphene support grids called GraFuture™ (including GraFuture™ GO and GraFuture™ RGO) to overcome challenges in sample preparation like severe preferred orientation, high background noise, and damage from the air-water interface. These grids are suitable for applications involving small protein molecular weight or low concentration samples.

These core strengths enable Shuimu BioSciences to provide efficient and accurate cryo-EM services tailored for achieving the highest possible resolution.

Navigating the Workflow: From Gene to High-Res Structure

Shuimu's "One-Stop" solution streamlines the entire process of obtaining high-resolution 3D structures. The typical workflow for Single Particle Analysis (SPA), a key cryo-EM method for revealing high-resolution 3D structures of biological macromolecules, illustrates this seamless process:

1. Project Consultation & Discussions: Initial engagement to understand research objectives.

2. Feasibility Evaluation: A complimentary assessment of project feasibility.

3. Strategy Definition: Development of a tailored experimental strategy.

4. Contract & Payment: Formalizing the service agreement.

5. Protein Expression & Purification: Preparation of high-quality target protein samples. Shuimu offers a complete platform featuring molecular cloning, protein expression, purification, and characterization to minimize variability.

6. Negative Staining: Initial observation and assessment of sample quality and particle homogeneity.

7. Sample Freezing & Data Collection: Preparing cryogenic samples and collecting extensive 2D images using cryo-EM instruments. Shuimu provides 24-hour instrument access for data acquisition.

8. 2D Particle Picking & 3D Reconstruction: Using computational algorithms to process 2D images and reconstruct a detailed 3D structural model. AI-driven software like SMART assists in this process.

9. Model Refinement: Optimizing the 3D model for accuracy and resolution.

10. Data Delivery: Providing the final high-resolution 3D structural model and associated data.

This integrated workflow, supported by dedicated teams and advanced technologies, ensures that clients can efficiently move from their target gene or protein to a high-resolution structure.

Comprehensive Cryo-EM Services for High-Resolution Analysis

Shuimu offers a range of cryo-EM services specifically designed for high-resolution structural analysis of diverse biological targets:

· One-Stop SPA Solutions: This is a powerful approach integrating cryo-EM to unveil high-resolution 3D structures of biological macromolecules like proteins, viruses, antigen-antibody complexes, small molecule targets, PROTACs, membrane proteins (GPCRs, ion channels, transporters), VLPs, and peptides. SPA preserves samples close to their native state, captures diverse conformations, requires minimal sample volume, and can determine heterologous protein complexes. Shuimu’s SPA solutions are bolstered by proprietary technologies like GraFuture™ grids, which help overcome challenges posed by small protein molecular weight, low concentration, high background noise, and preferential orientation.

· MicroED Solutions: Micro-electron diffraction (MicroED) is a cutting-edge technology that allows for the precise resolution of high-resolution structures from microcrystals and nanocrystals. This is particularly suitable for small molecule drugs, peptides, and protein crystals. Shuimu leverages its expertise and proprietary eTasED software to provide accurate structural insights, achieving impressive resolutions of 0.6~1.0Å for over 80% of their MicroED projects.

· Cryo Characterization: Utilizing ultra-low temperature technology, cryo-characterization maintains the natural state of samples for high-resolution structural observation and analysis. This service is particularly valuable for observing the structure and characteristics of AAVs, liposomes, LNPs, VLPs, exosomes, and material interfaces. Shuimu's self-developed AI cryo-EM system, NanoSMART, automatically identifies nanoparticle features from various electron microscope images, providing detailed reports on size distribution, roundness, and layered full/empty integrity.

· Negative Staining & 2D Negative Staining: Used for initial low-resolution observation of macromolecular complexes and particle homogeneity assessment. While not high-resolution in the same vein as SPA or MicroED, it's a crucial preliminary step to assess sample quality, particle size, uniformity, morphology, and integrity at a lower cost before pursuing high-resolution studies. This service is applicable to plant and animal tissue sections, proteins (AAV, exosomes, membrane proteins, viruses, soluble proteins), and other microscopic structures.

Each of these services contributes to Shuimu's ability to deliver comprehensive cryo-EM services and robust high-resolution structural analysis.

To learn more about the specific cryo-EM services offered by Shuimu BioSciences and discuss how they can help you achieve high-resolution structural analysis for your research goals, please visit https://shuimubio.com/.

Essential Support: Protein Preparation and Analysis

Obtaining high-resolution structures hinges on the quality of the protein sample. Shuimu BioSciences provides a complete platform for protein expression, purification, and analysis, seamlessly integrated with their cryo-EM services. This "One-Stop" approach minimizes variability and standardizes the entire pipeline, successfully addressing the challenges posed by difficult-to-express proteins.

Their protein platform offers:

· Protein Expression Systems: Expertise in four main systems: E. coli, mammalian cells, insect cells, and cell-free systems. Each system has distinct advantages, from the economy and speed of E. coli for prokaryotic or simple eukaryotic proteins to the post-translational modifications and native state production offered by mammalian cells for therapeutic proteins, vaccines, and antibodies.

· Protein Purification Processes: Utilizing various chromatography methods including Affinity chromatography, Ion-exchange chromatography, Gel filtration, and Reverse-phase HPLC (RP-HPLC) to ensure high sample purity. They have extensive experience in the production and purification method design of challenging membrane proteins like GPCRs, ion channels, and transporters.

· Protein Quality Control: Implementing strict quality control using techniques such as SDS-PAGE, Western blot, mass spectrometry, thermal stability and solubility testing. Protein purity is critical for cryo-EM studies, typically requiring >90-95% purity.

· Protein Assays: Offering services like SPR, BLI, and ELISA for protein analysis, interaction studies, and antibody characterization. These techniques are crucial for assessing protein-protein or protein-molecule binding analysis and characterizing antibody activity.

· Off-the-Shelf Protein List: Providing access to a list of important drug targets, including many membrane proteins like GPCRs, ion channels, transporters, and kinases. Custom protein target services are also available.

By integrating these upstream capabilities, Shuimu ensures that samples submitted for cryo-EM are of the highest quality, maximizing the chances of successful high-resolution structural analysis.

Sample Submission Requirements: Preparing for High-Res

Proper sample preparation and submission are paramount for successful cryo-EM experiments. Shuimu provides detailed requirements for various sample types to ensure optimal results.

Key requirements often include:

· Protein Solutions: Concentration typically ≥ 2mg/mL, volume ≥ 100ul, and purity ≥ 90% (often >95% for optimal results). Buffers should minimize organic solvents like glycerol and detergents, with salt ion concentration generally ≤ 300mM. Reducing glycosylation or phosphorylation modifications and minimizing freeze-thaw cycles are recommended. Freshly prepared or carefully stored samples are preferred.

· Small Molecules (for SPA or co-crystallization): Purity >95%, sufficient quantity (e.g., >10mg for SPA, >0.5mg for crystallography). Solubility in appropriate buffers (e.g., DMSO or water) is required. For SPA with a target protein, providing affinity data (nanomolar level) is helpful.

· Crystals (for MicroED or Crystallography): Samples must be stable crystals, in powder or lump form. Purity should be high (>95%), with specific requirements for concentration and total amount for crystallography.

· Cryo-Samples (for instrument access): Delivered to the EM Center at least 1 working day in advance via liquid nitrogen tanks. Avoiding repeated freeze-thaw cycles is crucial.

· Specific Sample Types (Cryo Characterization): Liposomes (1mg/ml), Viruses (e.g., AAV, e13 power), LNPs (suggested ~10mg/ml). Sugar content <10% is recommended as higher levels affect contrast.

· Samples for SPR/BLI/ELISA: Purity >90% is essential. Specific concentration and volume requirements vary by technique. Buffers should be appropriate and free from interfering substances like glycerol or imidazole.

Clear labeling and advance notification for sample delivery are important for smooth processing. By adhering to these guidelines, clients contribute significantly to the success of the high-resolution analysis.

To review detailed sample submission requirements for your specific project and ensure your samples are optimally prepared for high-resolution structural analysis via Cryo-EM, consult with the experts at https://shuimubio.com/.

Applications of High-Resolution Cryo-EM Analysis

The insights gained from high-resolution structural analysis using cryo-EM have broad applications across life sciences and drug development. Shuimu BioSciences highlights key application scenarios:

· Analyzing Biomacromolecules: Cryo-EM SPA can reveal the high-resolution 3D structures of a wide range of biomacromolecules, including diverse proteins (membrane proteins like GPCRs, ion channels, transporters; enzymes), DNA and RNA structures, protein–nucleic acid complexes, and various viral particles (like SARS-CoV-2, Influenza virus). Understanding these structures is vital for deciphering functional roles.

· Vaccine Field: Cryo-EM services are integral to vaccine R&D. They enable viral structure analysis at near-atomic resolution, providing key insights into viral entry mechanisms and guiding vaccine design. Cryo-EM is also used for vaccine quality control, examining morphology, particle size, integrity, and aggregation. Furthermore, it clarifies antibody binding to vaccine antigens to optimize immunogenicity and enables rapid structural analysis of new viral variants to adjust vaccine designs. Successful applications include studies on SARS-CoV-2, Influenza Virus, and Measles Virus.

· Antibody Drugs: Cryo-EM plays a crucial role in antibody drug development. It reveals high-resolution 3D structures of antibody–antigen interactions, helping understand recognition mechanisms and binding sites. Cryo-EM is used to study how antibody drugs work, such as binding to targets and modulating signaling pathways, aiding the development of new therapies targeting viral mutations. Structural analysis helps optimize antibody design for higher affinity and specificity and assists in mapping conformational epitopes. Crucially, cryo-EM can resolve the structures of membrane protein targets (like GPCRs), which are important for understanding ligand binding and signal transduction, vital for developing antibodies against these targets. The speed and clarity of cryo-EM accelerate drug development processes.

Through these applications, Shuimu's cryo-EM services and ability to achieve high-resolution structural analysis provide invaluable support across the biotechnology and pharmaceutical industries.

Discover the full potential of high-resolution structural analysis for your specific research area by exploring the applications and case studies on the Shuimu BioSciences website: https://shuimubio.com/.

Success Stories: Cases in High-Res Structural Analysis

Shuimu's expertise in providing cryo-EM services for high-resolution structural analysis is demonstrated through numerous successful projects and publications.

Since 2017, their platform has provided high-quality cryo-EM and MicroED structures for over 400 clients. They have resolved over 300 proteins with exceptional <3.5Å resolution and successfully completed over 300 single particle projects. Their work has been published in top international journals, covering structures of ion channels, GPCRs, antigen-antibody complexes, spliceosomes, and more.

Examples include:

· Resolving the cryo-EM structure of the human GluN1-GluN2A subtype NMDA receptor bound with different small molecules.

· Studying the activation mechanism of histamine receptors and successfully resolving the structure of the H1R and rGq complex.

· Utilizing negative staining for the observation of animal and plant tissue sections and protein particle uniformity detection for samples like AAV, Exosomes, Membrane Proteins, Viruses, and Soluble Proteins.

· Showcasing the effectiveness of their NanoSMART system for cryo-characterization, demonstrating accurate identification and statistical analysis for liposomes and VLPs even under challenging image conditions.

· Successfully applying their eTasED MicroED technology to resolve structures of small molecules (Acetaminophen), peptides, and proteins (Proteinase K).

These case studies underscore Shuimu's proven track record in delivering high-quality, high-resolution structural data across a variety of sample types and research challenges.

Conclusion

For researchers and companies requiring detailed, high-resolution structural analysis of biological macromolecules, Shuimu BioSciences offers a world-class platform and comprehensive cryo-EM services. From integrated protein preparation to cutting-edge instrumentation, AI-driven analysis, and expert scientific support, Shuimu provides a seamless "One-Stop" solution designed for efficiency and accuracy. Their extensive experience, dedication to resolution, and proprietary technologies position them as a leading partner in structural biology and drug discovery.

To discuss your specific project needs and learn how Shuimu BioSciences can provide the high-resolution structural analysis critical for your success, visit https://shuimubio.com/ today.