Isolation and storage of cells for study underwent a significant transformation with the advancement of technology, becoming the backbone of cell banking today. Find out more about the difference between a master and a working cell bank, along with their implementation and challenges in this article.
The American Type Culture Collection cell bank stores over 4,000 human and animal cell lines, supplied by a range of donors and disease models (1). © Green Elephant Biotech.
Cell banking is a process of maintaining and preserving a population of cells in culture, so they can later be used in laboratory experimentation and clinical testing. Though storage of cells, provided by private clients for future use in autologous therapies is rare, this service is primarily performed by private cells banks (2). A cell banking facility’s protocols primarily include cell counting, monitoring growth rates, harvesting once necessary, and re-freezing available cells for storage.
In the context of Cell and Gene Therapies (CGT) development, cell banking is primarily driven by cost-effectiveness and logistical efficiency, as large-scale cultivation of any cell type can be both expensive and labor-intensive for researchers. Less commonly discussed reasons include the safety and reliability of the resulting biopharmaceuticals, since established protocols support genetic stability and adequate vitality of the cells (3).
Within this framework, a distinction is made between a master cell bank and a working cell bank. A master cell bank is defined as an aliquot of a single pool of cells prepared from a selected clone under defined conditions. The creation of a master bank containing a homogeneous population of cells, free from cross-contamination or external influence through cryopreservation, is typically regulated by entities such as the European Medicines Agency (EMA) (4).
The working cell bank, as the name suggests, is derived from the master bank and is intended for active use in research, manufacturing, or genetic manipulation that will permanently alter the nature of the cells (3). Though the principle of cell banking is straight-forward, its applications and current position in clinical translation have a range of perspectives, as described in this piece.
Unicellular cloning is scientifically advantageous
The creation of a cell bank begins with isolating cells, which can come directly from an animal, a plant, or a specific tissue. Once collected, these cells are placed into a primary culture and grown on a suitable substrate under conditions that support their replication. As the cells divide over many generations, only the strongest clones continue to grow, eventually forming a purified cell line.
From this point on, the cells can be genetically engineered with viral vectors or transformed to create a continuous cell line, one in which cell division does not naturally stop (5). In some cases, such as the cultures derived from malignant tissues, this step may look different or may not be required to the same extent.
Using a cell bank offers several advantages. It supports reproducibility by maintaining a consistent genetic composition of an organism, ensuring that the same cell line is always available for research and production. Furthermore, the development of CGT and biologics is facilitated to accelerate with the researchers having an immediate stock of cells on hand (5).
Cell banking also reduces costs by avoiding repeated cell line production and the associated work, such as quality control and contamination monitoring (4). The facility therefore enables standardized scalability, allowing workflows to continue smoothly without the need to update equipment at each stage of experimentation.
Applications of cell banking became a majority in pharma
Cell banks play an essential role in the production of vaccines and biopharmaceuticals, where reliable and continuous manufacturing is crucial. Consequently, companies that work with diploid strains or homogeneous cell cultures have strong incentives to generate, characterize, and maintain cell banks that meet international requirements and quality standards (4).
Common examples of cell lines stored in these banks include the HeLa cells, originally isolated from Henrietta Lacks in 1951 and immortalized for cancer research. Non-cancerous cell lines include the CHO (i.e., Chinese Hamster Ovary) cells — the most widely used mammalian cell line, and HEK-293 (i.e., Human Embryonic Kidney) cells, frequently preferred in CGT development. Many repositories are not restricted to animal cell, however, also storing bacteria, molds, and yeasts.
Among the notable cell bank repositories worldwide is the American Type Culture Collection, considered one of the largest existing banks that offers a range of cell lines and microorganisms. In Europe, the European Collection of Authenticated Cell Cultures focuses on well-characterized human and animal cell lines, including those mentioned above (6). Importantly, any repository must follow international quality management standards like ISO 9001 and ISO 13485 to ensure best practices in cell line handling and distribution.
Private cell banking – where convenience meets controversy
In a time when the promise of easily accessible cell, gene, and tissue therapies is increasingly promoted, both legitimate and questionable marketing services for private cell banking continue to appear. This is particularly evident in the area of umbilical-cord blood banking, where companies offer to store cells for future use in hematopoietic stem-cell transplantation and immune therapies.
Beyond the ethical concerns associated with offering potentially life-saving resources in exchange for private fees, there is also the risk that high standards for donor selection, collection, and shipment may not be consistently upheld within such organizations (2). In a sector shaped by strong financial incentives coupled with expanding demand, many for-profit cell banks operate within financial frameworks that simply cannot guarantee the necessary level of quality.
For this reason, health policymakers are encouraged to focus on developing and supporting public platforms that can limit the influence of private organizations and address these challenges. Making the application process for private individuals more transparent and user-friendly, especially with regard to consent, can further guide the public toward selecting regulated cell banks rather than private alternatives (7).
This article offers only a brief overview of the processes, applications, and global landscape in both public and private cell banks, although a substantial amount of general documentation is available for the readers.
Research and development of CGTs and biologics would be significantly more labor-intensive without the foundation that the cell banks provide. However, the risks associated with non-compliance in quality management at such facilities remain an important concern that cannot be overlooked.
Whether you are working with locally isolated cells or using samples from a cell bank, the goal at Green Elephant Biotech remains the same: to enable the seamless and conscious scale-up of adherent cell cultures. With CellScrew® and the Green Elephant Biotech® 96-well microPLAtes, you benefit from reduced carbon footprint and cost-effectiveness without compromising the quality or growth performance of your cell lines.
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References:
- What makes ATCC’s cell lines ideal for drug discovery, development, and manufacturing? (2024). ATCC. Available https://www.atcc.org/cell-products#t=productTab&numberOfResults=24 (Accessed 18 November 2025).
- Cell Banking for Cell and Gene Therapy: Regulatory, Ethical, and Scientific Considerations. (2020). BioProcess International. Available https://www.bioprocessintl.com/cell-therapies/cell-banking-for-cell-and-gene-therapy-regulatory-ethical-and-scientific-considerations (Accessed 17 November 2025).
- What exactly is cell banking? (2025). NorthX Biologics. Available https://www.nxbio.com/resource/what-exactly-is-cell-banking/ (Accessed 14 November 2025).
- Soleimani, S, Ghorani, M, Cell bank system, establishment, and application in the virus research, diagnosis, and biopharmaceutical industries (2025), Biotechnol Notes, pp. 209-221. doi: 10.1016/j.biotno.2025.08.001.
- Cell Cultures and Cell Banks. (2024). abbvie. Available https://www.abbviecontractmfg.com/news-and-insights/fun-science-friday/cell-culture-working-cell-banks.html (Accessed 14 November 2025).
- Weiskirchen, S, Monteiro, AM, Borojevic, R, Weiskirchen, R, Unlocking Potential: A Comprehensive Overview of Cell Culture Banks and Their Impact on Biomedical Research (2024), Cells, pp. 1861. doi: 10.3390/cells13221861.
- Gerdfaramarzi, MS, Bazmi, S, Kiani, M, Afshar, L, Fadavi, M, Enjoo, SA, Ethical challenges of cord blood banks: a scoping review (2022), J Med Life, pp. 735-741. doi: 10.25122/jml-2021-0162.
