Lentivirus Packaging Services

Lentiviral vectors combine stable genomic integration capacity with broad host cell tropism, making them ideal tools for achieving long-term transgene expression and establishing stable cell line models. As a preclinical CRO dedicated to the oncology field, Alfa Cytology provides high-quality lentivirus packaging services, committed to delivering efficient and stable gene delivery solutions for your research projects.

Introduction to Lentivirus Packaging

Lentivirus, a member of the Retroviridae family, has emerged as one of the most widely adopted gene delivery vehicles in cancer research, owing to its unique ability to infect both dividing and non-dividing cells and to stably integrate the transgene into the host genome. The lentiviral genome has been engineered into multiple separate plasmids, which preserves its potent transduction capacity while fundamentally eliminating the risk of autonomous viral replication. Lentiviral vector systems typically employ a three- or four-plasmid co-transfection strategy in packaging cells (e.g., HEK293T cells), wherein the gene of interest, packaging elements (gag/pol, rev), and envelope glycoprotein (commonly VSV-G) are distributed across distinct plasmids. This design substantially minimizes recombination events while enabling efficient and safe virus production. Through optimization of critical process parameters, including plasmid ratios, transfection reagents, and harvest timing, high-titer and high-purity viral stocks can be consistently obtained, meeting diverse requirements ranging from in vitro cellular assays to in vivo animal models. In oncology research, lentiviral vectors are extensively applied in gene overexpression, shRNA-mediated gene knockdown, CRISPR/Cas9-based gene editing, and genome-wide functional screening. Cells transduced with lentivirus achieve long-term, stable expression of the target gene or regulatory elements, providing an ideal tool for establishing stable cell lines, developing CDX models, and conducting in vivo engraftment studies.

Fig. 1 Workflow for lentiviral vector (LV) production. (Keyer V, et al.; 2025)

Our Services

Thanks to our well-established lentivirus packaging platform and full-process technical expertise, Alfa Cytology is committed to providing efficient, robust, and customizable lentiviral gene delivery solutions for oncology gene function studies and drug development, comprehensively accelerating the translational journey from target discovery to in vivo efficacy validation.

Vector Design and Construction

Based on your research objectives, we design and construct lentiviral vectors carrying genes of interest, shRNA, or CRISPR/Cas components. Our services include:

• PCR amplification and cloning of target genes
• shRNA sequence design and double-strand annealing ligation
• sgRNA design and vector construction
• Codon optimization (as required)
• Introduction of fusion tags (Flag, HA, GFP, etc.) and reporter genes
• Full-length sequencing verification to ensure 100% accuracy of inserted sequences

Virus Packaging and Production

Under a GMP-like quality control system, we employ an optimized four-plasmid co-transfection system for lentivirus packaging and production:

• High-quality endotoxin-free plasmid maxipreparation
• Liposome- or PEI-mediated co-transfection of 293T cells
• Serum-free culture system to avoid exogenous factor contamination
• Optimized harvest timing to maximize viral yield

Virus Purification and Concentration

Depending on your application requirements, we offer different levels of purification protocols:

• Standard Purification: 0.45 μm filtration to remove cellular debris
• Concentration Purification: Ultracentrifugation or PEG precipitation for virus concentration
• High-Purity Purification: Ion-exchange chromatography or sucrose density gradient centrifugation to effectively remove endotoxins, host DNA, and protein residuals, suitable for in vivo applications

Quality Control Testing

Each batch of lentivirus undergoes comprehensive quality control testing:

• Physical Titer: Quantitative detection of viral particle numbers via p24 ELISA
• Infectious Titer: Determination of functional titer (IU/mL) in standard cell lines by limiting dilution assay
• Purity Assessment: SDS-PAGE analysis and endotoxin testing
• Sterility Testing: Detection of bacteria, fungi, and mycoplasma
• Activity Validation: Verification of transgene expression or regulatory efficiency in target cells

Specifications

Applications of Lentiviral Vectors in Cancer Research

Alfa Cytology integrates an advanced lentiviral production platform with rigorous project management and exceptional scientific capabilities. Whether you are establishing stable cell lines, conducting in vivo transplantation experiments, or advancing gene therapy candidates, we are your trusted partner in accelerating cancer research. Please feel free to contact us to discuss your project and learn how Alfa Cytology can support your drug discovery journey.

For research use only.