In the field of cell and gene therapy (CGT), Excell Bio provides you with end-to-end cell and gene therapy solutions to help you develop therapies that can save lives. Our mission is to build Bridges to help you reach your next milestone, to help you progress, and to drive your cell and gene therapy success. We provide you with high-quality materials, services and support to help you accelerate your workflow from research discovery to clinical research to commercial production.
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Construction of vector
The construction of vectors is a foundational step in cell and gene therapy. It involves the precise design and synthesis of DNA sequences to carry therapeutic genes. These sequences are then cloned into suitable vector backbones using molecular biology techniques such as restriction enzyme digestion and ligation. The resulting constructs are validated through DNA sequencing and tested in small-scale cell cultures to ensure they express the desired gene product accurately. This meticulous process ensures that the vectors are ready for efficient gene delivery.
Transfection with lentivirus packaging
Transfection is a critical process where lentiviral packaging plasmids and target vectors are prepared. High-efficiency transfection reagents are utilized to introduce the DNA into packaging cells, typically 293T cells. The cells are monitored for viral particle production, and the supernatant is harvested at optimal time points, usually 48, 72, and 96 hours post-transfection. The harvested supernatant is then filtered and centrifuged to remove cellular debris, yielding a purified lentiviral vector. This step is essential for the successful integration of genetic material into target cells, ensuring high transduction efficiency.
Cell expansion
Cell expansion is a key phase in scaling up cell populations for therapeutic use. Transduced cells are seeded in appropriate culture vessels, such as cell culture flasks or bioreactors, and incubated under controlled conditions to promote growth. The culture medium provides the necessary nutrients, and parameters such as temperature, CO2 levels, and humidity are carefully maintained. Cell density and viability are regularly monitored using techniques like flow cytometry and trypan blue exclusion. This ensures that the cells are healthy and proliferating at an optimal rate, providing a sufficient cell mass for downstream applications.
Cell cryopreservation
Cryopreservation is vital for the long-term storage and preservation of cell products. Cells are harvested and resuspended in a cryopreservation medium that protects them from freezing damage. They are then aliquoted into cryogenic vials and subjected to a controlled freezing process to prevent the formation of ice crystals that could damage the cells. The vials are stored in liquid nitrogen, which maintains a temperature of around -196°C, ensuring the cells remain viable for extended periods. This process allows for the banking of cells, facilitating their use in future treatments and research.
Quality control and release
Quality control is an indispensable component of cell and gene therapy production. Throughout the manufacturing process, in-process testing is conducted to ensure that the cells and vectors meet stringent quality standards.
