The fermentation of hybridoma cells refers to the process of culturing and growing hybridoma cells in a bioreactor under controlled conditions to produce monoclonal antibodies.
Hybridoma cells are a fusion of B-lymphocytes (derived from the immune system of a mouse or other animal) and myeloma cells (cancerous cells derived from the bone marrow of a mouse). These hybrid cells possess the ability to continuously produce large quantities of a specific monoclonal antibody.
A general overview of the fermentation process for hybridoma cells
Cell Culture Medium Preparation
A suitable culture medium is prepared, typically consisting of a nutrient-rich base medium supplemented with essential nutrients, growth factors, salts, and other components required for cell growth.
Hybridomas have traditionally been cultured in serum supplemented media. However, it is a complex and ill-defined mixture of proteins and nutrients. The precise composition depends on the source and type of serum. Serum-free media is preferred because the removal of other animal proteins means purification is simpler, especially the elimination of serum immunoglobulin contamination. Thus, the overall protein content is much lower than with other media. If a hybridoma is a low-level producer of monoclonal antibodies, it makes it much easier to purify even those amounts if starting proteins are absent (Tharakan & Chau, 1986).
Inoculum Expansion
A small number of hybridoma cells, known as the inoculum, is added to a small-scale culture vessel. The cells are allowed to grow and multiply under optimal conditions until they reach a desired cell density. This step serves as a starting point for the larger fermentation process.
Bioreactor Setup
The culture medium and the expanded inoculum are transferred to a larger-scale bioreactor, which provides a controlled environment for cell growth. The bioreactor typically consists of a vessel equipped with sensors to monitor and control various parameters like temperature, pH, dissolved oxygen, and agitation.
Fermentation Process
The hybridoma cells are incubated in the bioreactor, and the culture conditions are optimized for their growth and antibody production. The culture medium is continuously circulated and aerated to ensure an adequate supply of oxygen and nutrients.
Monitoring and Control
Throughout the fermentation process, various parameters are monitored and adjusted to maintain optimal conditions for cell growth. This includes monitoring cell density, viability, nutrient levels, pH, and dissolved oxygen. Adjustments may be made to the culture conditions to enhance antibody production.
Harvesting
When the hybridoma cells have reached their peak antibody production, the culture is harvested. The cells are typically separated from the culture medium using methods such as centrifugation or filtration. The resulting supernatant or cell lysate contains the secreted monoclonal antibodies.
Purification
The harvested material undergoes purification processes to isolate and purify the monoclonal antibodies. These processes may include filtration, chromatography, and other techniques to remove impurities and obtain highly concentrated and pure antibodies.
Formulation and Packaging
The purified monoclonal antibodies are formulated into a final product, which may involve buffer exchange, concentration adjustment, and sterile filtration. The antibodies are then packaged into vials or other suitable containers for storage and distribution.
The fermentation of hybridoma cells provides a scalable and efficient method for the production of monoclonal antibodies, which are widely used in research, diagnostics, and therapeutic applications.
References
Tharakan, J. P., & Chau, P. C. (1986). Serum free fed batch production of IgM. Biotechnology Letters, 8, pp. 457-462
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