About Us

Nebulabio is a dedicated contract development and manufacturing organization (CDMO) specializing in high-yield, scalable recombinant antibody production using Chinese Hamster Ovary (CHO) expression systems. Our mission is to bridge the gap between antibody discovery and clinical application by providing robust, GMP-ready processes for the production of monoclonal antibodies, bispecifics, antibody fragments, and fusion proteins. We combine deep expertise in mammalian cell culture, process optimization, and analytical development to deliver biologics of the highest quality, consistency, and activity. Whether you need research-grade material for proof-of-concept studies, gram-to-kilogram quantities for preclinical development, or process development and tech transfer for cGMP manufacturing, we are your strategic partner. We are committed to accelerating your timeline from sequence to purified protein with scientific rigor, transparent communication, and a focus on your success.

☞Introduction to Recombinant Antibody

Recombinant antibodies are monoclonal antibodies produced by introducing their genetic blueprint into a host cell system, which then serves as a living factory for protein synthesis. This method offers unparalleled control over antibody sequence, isotype, format (e.g., IgG, scFv, bispecifics), and quality, superseding traditional animal-based methods.

For therapeutic and high-value reagent production, Chinese Hamster Ovary (CHO) cells are the industry gold standard, primarily due to their ability to perform human-compatible post-translational modifications (PTMs), especially complex glycosylation. This is critical for antibody stability, serum half-life, and effector functions (e.g., ADCC). Beyond PTMs, CHO cells offer a proven safety profile, excellent scalability in bioreactors, and through advanced engineering, can achieve very high productivity.

A critical factor in successful CHO expression is the design of the expression vector, which directly impacts antibody yield, quality, and the stability of the production cell line. The choice of vector strategy involves trade-offs between expression level, genetic stability, and the balanced production of heavy and light chains. Common strategies include:

• Monocistronic Vectors: Utilize separate vectors or genetic loci for heavy chain (HC) and light chain (LC), often driven by strong promoters like CMV or SV40. This allows for proportional coordination but increases the screening workload.

• Bicistronic/Multipromoter Vectors: Incorporate both HC and LC genes in a single vector, each under its own promoter (e.g., CMV, EF-1α). This can boost titers but may lead to promoter interference and imbalanced expression over time.

• IRES-mediated Vectors: Use an Internal Ribosome Entry Site (IRES) to co-express two genes from a single mRNA transcript. This ensures coordinated transcription but often results in lower expression of the downstream gene.

• Furin-2A-mediated Vectors: Employ self-cleaving 2A peptides to produce multiple proteins from one mRNA. This allows for efficient, stoichiometric co-expression but may leave short residual amino acid sequences on the protein.

The selection and optimization of the expression vector are therefore foundational steps in our cell line development process, ensuring the generation of stable, high-yielding clones that produce antibodies with consistent quality. Our expertise allows us to select and tailor the most appropriate vector system for your specific antibody molecule, balancing the advantages of high titer with the requirements for proper assembly and product quality.

☞Recombinant Antibody Production Development Process

Our development pathway is designed to build a robust, scalable, and high-yielding process.

①Gene Synthesis & Vector Construction: Your antibody sequence is codon-optimized for CHO cells and cloned into our high-expression mammalian vectors, which include strong promoters (CMV, EF-1α) and selectable markers (e.g., GS, DHFR).

②Cell Line Development: This critical phase involves:

• Transfection: Introducing the expression vector into a proprietary host CHO cell line.

• Selection & Single-Cell Cloning: Applying selective pressure to isolate stable pools, followed by isolation of single cells to generate clonal populations.

• Screening & Clone Selection: High-throughput screening of hundreds of clones for growth, viability, and antibody titer. The top producers are evaluated for product quality attributes (glycosylation, aggregation) and genetic stability.

• Master Cell Bank (MCB) Generation: The selected lead clone is expanded to create a characterized, cryopreserved MCB, ensuring a consistent starting point for all future production.

③Upstream Process Development: We optimize the cell culture conditions for the selected clone, including:

• Media & Feed Strategy: Development of a tailored, chemically defined feeding regimen to maximize cell density and productivity.

• Bioreactor Process Development: Scaling from shake flasks to bench-top bioreactors, optimizing parameters like pH, dissolved oxygen (DO), temperature, and feeding schedules to establish a reproducible fed-batch or perfusion process.

④Downstream Process Development: A purification strategy is designed and optimized for your specific antibody:

• Harvest & Clarification: Centrifugation and depth filtration to remove cells and debris.

• Capture: Typically Protein A affinity chromatography.

• Polishing: A series of steps (e.g., CEX, AEX, HIC) to remove aggregates, host cell proteins, DNA, and leached Protein A.

• Viral Clearance/Inactivation: Incorporation of dedicated steps (low-pH hold, virus filtration, solvent/detergent treatment) for regulatory compliance.

• Formulation & Ultrafiltration/Diafiltration (UF/DF): Final purification and concentration into the desired formulation buffer.

⑤Analytical Development & Quality Control (QC): Parallel development of robust analytical methods (SEC-HPLC for aggregates, CE-SDS for purity, HPLC for glycan analysis, potency assays) to fully characterize the product and support lot release.

☞Nebulabio’s Service Process

Our client-focused process ensures clarity and collaboration from initial contact to final delivery.

• Step 1: Project Consultation & Sequence Analysis. We discuss your project goals, quantity needs, and quality requirements. Our scientists analyze your antibody sequence for potential expression or stability issues.

• Step 2: Cell Line Development. We perform transfection, single-cell cloning, and multi-tiered screening to deliver a high-producing, stable research cell bank (RCB) or Master Cell Bank (MCB), complete with characterization data.

• Step 3: Process Development & Optimization. We develop and lock down the upstream fed-batch process and the downstream purification scheme, establishing critical process parameters (CPPs).

• Step 4: Scale-up Production. The developed process is executed at the agreed scale (from bench-top to pilot-scale bioreactors) to produce your target batch size.

• Step 5: Purification, Formulation & QC. The harvest is processed through the purification train, formulated, and subjected to a full battery of release testing.

• Step 6: Final Delivery. You receive the purified, bottled antibody, along with a comprehensive Certificate of Analysis and a detailed technical development report.

☞Nebulabio’s Service Advantages

• Platform Process with Customization: We leverage a highly optimized platform for CHO-based antibody production, which we rapidly tailor to your specific molecule, significantly reducing development time and cost.

• High-Titer Cell Line Development Expertise: Our proprietary host lines and advanced screening technologies consistently yield clones with superior productivity, giving you more material faster and reducing COGS.

• Integrated Development from Clone to Vial: We offer a true one-stop-shop, managing the entire continuum from vector to purified drug substance under one roof, ensuring seamless knowledge transfer and accountability.

• Focus on Product Quality & Regulatory Readiness: Our processes are designed with regulatory submission in mind. We emphasize critical quality attributes (CQAs), implement robust viral clearance strategies, and generate comprehensive data packages to support IND/IMPD filings.

• Scalability and Technology Transfer Support: Our processes are developed with scalability as a core principle. We provide full support for technology transfer to your internal facility or a GMP manufacturing partner.

• Dedicated Project Management & Scientific Collaboration: You are assigned a dedicated project manager and lead scientist, ensuring clear communication, timely updates, and access to expert advice throughout the project lifecycle.

☞Accelerate Your Biologics Pipeline

Trust Nebulabio’s expertise in CHO-based recombinant antibody production to deliver the high-quality, scalable material you need to advance from candidate selection to clinical trials. We are committed to providing a partnership that combines scientific excellence with operational reliability, ensuring your project’s success.