Nebulabio is a protein science team dedicated to producing complex recombinant proteins using the baculovirus–insect cell expression system. By integrating eukaryotic construct strategy, insect cell culture, and virology-based production workflows, we deliver proteins that require proper folding, oligomerization, and post-translational processing for structural and functional studies. The service is positioned for research and preclinical discovery contexts that require structurally authentic material and traceable QC documentation.
☞Nebulabio’s Baculovirus-Insect Cell Expression Platform
The baculovirus–insect cell system is a versatile eukaryotic expression platform in which insect cells such as Sf9, Sf21, or High Five are infected with recombinant baculoviruses carrying the gene of interest under strong viral promoters. This system supports production of multi-domain proteins, secreted glycoproteins, and multi-subunit complexes that are often difficult to express in prokaryotic hosts. Our platform provides end-to-end execution from gene readiness and transfer vector design to bacmid generation, virus amplification, expression, purification, and characterization, enabling reliable protein supply for demanding downstream applications.
| ☎ +86-15801534258 | ✉ info@nebulabio.cn | Contact Us ☜☜ |
☞Supported Options
| Host Insect Cell Lines | Vectors and Bacmid Systems |
• Sf9 and Sf21 • High Five (BTI TN 5B1 4) • Suspension or adherent formats with serum-free adaptation when applicable | • Transfer vectors such as pFastBac pOET or custom backbones • Viral promoters including polyhedrin and p10 • Tags and secretion signals including His GST Fc Strep II and GP67 or honeybee melittin • Multi-gene configurations for complexes and accessory factors |
| Virus Generation and Amplification | Expression and Production Modes |
• Bacmid generation through site-specific transposition in E. coli • P1 generation followed by P2 and P3 amplification • Titer determination by plaque assay or TCID50 when configured • High-titer working stocks upon request | • Small-scale expression screening in multiple cell lines • Scale-up in shake flasks or bioreactors • Secreted or intracellular production routes defined by construct design |
| Purification and Characterization | |
• Affinity capture and polishing by ion exchange hydrophobic interaction or size exclusion chromatography • Tag removal options using TEV thrombin or PreScission protease • Buffer exchange and concentration into storage or assay conditions • Optional glycosylation profiling when configured |
☞Principle of Baculovirus-Insect Cell Expression
The baculovirus–insect cell system produces recombinant proteins by engineering a baculovirus genome to carry the gene of interest under a strong viral promoter, then infecting insect cells to drive high-level expression. Insect cells provide eukaryotic folding and processing capacity, supporting disulfide bond formation, oligomer assembly, and N-linked glycosylation that is generally simpler and high-mannose enriched compared with mammalian patterns. The system is frequently used for multi-domain proteins, membrane-associated targets, viral antigens, enzymes, and protein complexes where eukaryotic processing is required for functional or structural integrity. Compared with bacterial expression, it offers improved folding and processing capabilities, and compared with mammalian platforms it often provides efficient yields and scalable research production routes.
☞Nebulabio Service Workflow
Project Design and Construct Cloning We define a baculovirus–insect cell strategy aligned with target complexity and downstream assay requirements. Key Steps • Gene readiness review and codon adaptation for insect expression contexts • Transfer vector selection aligned with promoter tag and secretion signal logic • Bacmid generation through transposition workflow • Sequence verification to confirm insert integrity and reading frame |
Virus Generation and Titering We generate recombinant virus and establish a controlled infection context for reproducible expression. Key Steps • Transfection of insect cells with bacmid DNA to produce P1 virus • Harvest of P1 supernatant at defined post-transfection window • Amplification to P2 and P3 working stocks when required • Titer determination by plaque assay or TCID50 when configured |
Expression Screening and Condition Definition We evaluate expression behavior across cell lines and harvest windows to establish a scale-up route. Key Steps • Small-scale infections in Sf9 Sf21 and High Five as applicable • Infection parameter exploration across MOI and time-course windows • Analytical confirmation using SDS PAGE Western blot and project-defined activity checks • Assessment of secretion behavior for secreted formats |
Scale Up Protein Production We execute larger-volume infections under defined conditions in suspension culture formats. Key Steps • Expansion in serum-free suspension culture when applicableWe evaluate expression behavior across cell lines and harvest windows to establish a scale-up route. • Small-scale infections in Sf9 Sf21 and High Five as applicable • Infection parameter exploration across MOI and time-course windows • Analytical confirmation using SDS PAGE Western blot and project-defined activity checks • Assessment of secretion behavior for secreted formats • Infection at defined MOI in shake flasks or bioreactors • Monitoring of cell viability expression trajectory and harvest timing • Harvest of clarified supernatant or cell pellet processing depending on format |
Purification and Refinement We purify and polish the target protein to the agreed purity and homogeneity tier. Key Steps • Affinity capture aligned with tag choice • Optional tag removal with corresponding cleanup • Polishing by ion exchange size exclusion or hydrophobic interaction chromatography as configured • Concentration and buffer exchange into storage or assay conditions |
Quality Control and Characterization We generate a traceable characterization package supporting identity purity processing state and functional attributes. Key Assays • Purity and homogeneity assessment by SDS PAGE and SEC HPLC when configured • Concentration determination using standard quantification methods • Identity support by mass spectrometry when configured • Glycosylation profiling by lectin blot or MS-based analysis when configured • Activity or antigenicity testing aligned with project-defined endpoints |
Delivery and Reporting We deliver aliquoted protein material and complete documentation for reproducible downstream use. Deliverables • Purified protein aliquots with defined storage condition • COA and QC summary with full data package • Optional virus stock for future runs when configured • Handling and storage guidance including reconstitution notes when relevant |
☞Featured Applications of Nebulabio’s Services
● Structural Biology and Cryo EM
The baculovirus–insect cell system is commonly used to produce multi-subunit complexes and conformationally sensitive proteins where eukaryotic folding supports structural integrity. It enables preparation of relatively homogeneous material that can be further polished for crystallography cryo EM or biophysical characterization.
● Vaccine Antigen and VLP Production
Insect cells can express viral envelope proteins capsid components and VLP-related assemblies with native-like conformation in many contexts. This supports antigenicity-relevant presentations and provides scalable material supply for comparative evaluation of antigen formats.
● Therapeutic Format Proteins and Fc Fusions
Eukaryotic folding capacity supports production of cytokines growth factors and Fc-fusion formats where disulfide pairing and secretion processing influence integrity. The system can provide research-grade material with documented purity and processing features for preclinical evaluation contexts.
● Membrane Proteins and Receptor Studies
Baculovirus expression is frequently applied to GPCRs transporters and receptor ectodomains where eukaryotic processing supports stability and functional presentation. Co-expression designs can be used for multi-subunit receptors or accessory factors when defined by the project.
For more information, please contact us at info@nebulabio.cn or +86-15801534258.
