CD Biosynsis offers premium Mammalian Cells Protein Expression and Purification Services, utilizing industry-standard hosts like CHO (Chinese Hamster Ovary) cells and HEK293 cells for the high-quality, large-scale production of complex biotherapeutics. Mammalian cells are the established system for producing proteins that require accurate post-translational modifications (PTMs), correct disulfide bond formation, and native assembly for clinical use, including monoclonal antibodies (mAbs), fusion proteins, and biosimilars. Our comprehensive service spans from gene synthesis and vector construction (plasmid or stable integration) to high-cell-density fed-batch fermentation and multi-step chromatography for high-purity protein isolation. We guarantee the production of functional, correctly folded proteins, ensuring clients receive high-quality material for downstream applications in clinical trials, drug screening, and structural biology.
Get a QuoteThe key advantage of using Mammalian Cells is their ability to perform human-compatible protein processing. This includes the endoplasmic reticulum (ER) and Golgi apparatus, which are essential for processing, folding, and secreting proteins that require complex N- and O-linked glycosylation, disulfide bridges, and native assembly for functionality. Our platform leverages optimized expression vectors, advanced cell line engineering techniques (e.g., anti-apoptosis knockouts), tailored high-cell-density fed-batch culture protocols, and efficient purification strategies to maximize soluble, active protein yield. This focus on mammalian fidelity ensures the final purified protein meets stringent regulatory and quality standards.
Codon Optimization
Rational design and optimization of the target gene sequence to match the specific host cell's codon usage and GC content, significantly enhancing translation efficiency and total protein titer.
Stable Cell Line Generation
Creation of stable, high-expressing clones through random integration followed by selection/amplification (DHFR/GS systems) or targeted CRISPR-mediated knock-in into genomic safe harbor sites.
Fed-Batch Fermentation
Optimization of media and feeding strategies for high-cell-density culture (HCDC), maximizing the specific productivity ($\text{Q}_{\text{p}}$) and culture longevity of the production cell line.
Affinity Chromatography (AC)
Primary capture using highly specific methods (e.g., Protein A/G for mAbs, or His-tag/Strep-tag) from the large-volume culture supernatant to achieve high initial purity.
Ion Exchange Chromatography (IEX)
Used as a polishing step to remove residual Host Cell Proteins (HCPs) and address product charge variants (e.g., deamidation, aggregation), crucial for biotherapeutic homogeneity.
Viral Inactivation/Filtration
Mandatory steps (low pH incubation, specific filtration) incorporated into the purification train to meet regulatory requirements for the safety of mammalian-expressed biopharmaceuticals.
Monoclonal Antibodies (mAbs)
Standard production of IgGs, IgMs, bispecific antibodies, and antibody fragments, ensuring native assembly and the desired human-like N-glycan profile.
Complex Glycoproteins
Expression of therapeutic proteins (e.g., erythropoietin, clotting factors) that require complex, native N-linked and O-linked glycosylation patterns for biological activity and half-life.
Recombinant Vaccines/Antigens
High-yield production of multi-subunit protein antigens and viral surface proteins that require correct disulfide linkage and folding for immunogenicity.
A systematic process from gene design to final quality-controlled biotherapeutic product.
1. Gene & Vector Design
2. Stable Cell Line Generation
3. Bioreactor Culture & Harvest
4. Multi-Step Purification & QC
Codon optimize gene for the specific host; design purification tags and required regulatory elements.
Clone gene into DHFR/GS selection vector or CRISPR knock-in cassette for chromosomal integration.
Perform small-scale transient expression to confirm protein quality and yield.
Transfect host cells and select/amplify clones (e.g., Methotrexate for DHFR) to isolate high-producers.
Screen clones using HTS (ELISA/FACS) to identify High-Producer clones; establish master cell bank (MCB).
Select the final clonal cell line based on titer, product quality, and genetic stability.
Purification: Execute multi-step chromatography (Affinity, IEX, SEC) and necessary viral inactivation/filtration steps.
QC: Purity analysis (SDS-PAGE/CE-SDS), identity (Mass Spec), Glycan Analysis, and Functional Assay.
Delivery of purified protein, Certificate of Analysis (CoA), and documentation of all upstream/downstream protocols.
Regulatory Acceptance
CHO cells are the most widely accepted mammalian production system by global regulatory bodies (FDA/EMA) for manufacturing commercial biopharmaceuticals.
Accurate Human PTMs
The host performs correct protein folding, disulfide bond formation, and, crucially, human-compatible glycosylation essential for drug efficacy and safety.
Scalability & Titer
Our optimized HCDC fed-batch protocols and high-producer cell lines achieve superior volumetric productivity, ensuring cost-effective scalability for commercial supply.
Integrated Quality Control
Purification protocols include necessary viral clearance and high-resolution chromatography steps to achieve high purity and address critical quality attributes (CQAs) like aggregation and charge variants.
1. What types of proteins are best expressed in mammalian cells?
Mammalian cells are ideal for complex glycoproteins, especially those requiring proper disulfide bonding, dimerization, and human-like N-linked glycosylation, such as monoclonal antibodies (mAbs), fusion proteins, and hormones.
2. How is a stable, high-producing cell line established?
We use vector integration systems (DHFR/GS) or CRISPR-Cas9 targeted knock-in, followed by antibiotic selection and gene amplification, and finally, single-cell cloning using FACS to isolate the highest-producer clones.
3. Do you offer services to optimize the protein's glycan profile?
Yes. We use advanced gene editing (CRISPR/Base Editing) to modify host cell glycosylation enzymes (e.g., FUT8 KO, GNAT) to achieve the desired human-like N-glycan structure and improve therapeutic efficacy.
4. What is the role of the DHFR/GS system in stable cell line generation?
The DHFR (Dihydrofolate Reductase) and GS (Glutamine Synthetase) systems allow for metabolic selection and gene amplification. By treating the cells with Methotrexate or MSX, the cells are forced to increase the copy number of the integrated therapeutic gene, significantly boosting titer.
5. How is the final purified product's quality verified?
Final QC includes CE-SDS or SDS-PAGE for purity and aggregation, Mass Spectrometry (MS) for identity and molecular weight, isoelectric focusing (IEF) for charge profile, and full glycan analysis.
6. What fermentation culture mode is used for large-scale production?
We utilize optimized fed-batch culture protocols in stirred-tank bioreactors. This High-Cell-Density Culture (HCDC) approach provides the necessary scalability, titer, and control required for industrial GMP manufacturing.
7. What is included in the documentation package?
We provide a comprehensive Certificate of Analysis (CoA) for the purified protein, stability data for the Master Cell Bank (MCB), and detailed protocols for the upstream (cell culture) and downstream (purification) processes.
8. How do you ensure the genetic stability of the cell line?
Stability is ensured by selecting clones with integration into defined genomic safe harbor loci (via CRISPR/HDR) and verifying stable productivity over many generations (typically 60-90 population doublings).
CRISPR-Cas9 technology represents a transformative advancement in gene editing techniques. The main function of the system is to precisely cut DNA sequences by combining guide RNA (gRNA) with the Cas9 protein. This technology became a mainstream genome editing tool quickly after its 2012 introduction because of its efficient, simple and low-cost nature.
The CRISPR gene editing system with its Cas9 version stands as a vital instrument for current biological research. CRISPR technology enables gene knockout (KO) through permanent gene expression blockage achieved by sequence disruption. Various scientific domains including disease modeling and drug screening employ this technology to study gene functions. CRISPR KO technology demonstrates high efficiency and precision but requires confirmation and verification post-implementation because unsatisfactory editing may produce off-target effects or incomplete gene knockouts which impact experimental result reliability. For precise and efficient Gene Editing Services - CD Biosynsis, Biosynsis offers comprehensive solutions tailored to your research needs.
The CRISPR-Cas9 knockout cell line was developed using CRISPR/Cas9 gene editing to allow scientists to remove genes accurately for research on gene function and disease models and pharmaceutical discovery. Genetic research considers this technology essential due to its high efficiency together with simple operation and broad usability.
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CD Biosynsis is a leading customer-focused biotechnology company dedicated to providing high-quality products, comprehensive service packages, and tailored solutions to support and facilitate the applications of synthetic biology in a wide range of areas.