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Hybridoma-technologie
Hybridomatechnologie wordt gebruikt voor de grootschalige productie van monoklonale antilichamen. Monoklonale antilichamen binden slechts aan één enke…
Hybridoma technology is used to mass-produce monoclonal antibodies that can only bind to a single epitope — part of an antigen that elicits an immune response.
The process starts with injecting a mouse with a target antigen and then harvesting its spleen after a few weeks to isolate antibody-producing B cells. These cells have a limited life span and cannot be cultured in a lab.
Next, the B cells are fused with myeloma cells — immortal and cancerous white blood cells, using electric pulses or polyethylene glycol. Thus, forming hybrid immortal, antibody-producing cells called hybridomas.
Hybridomas are further selected on hypoxanthine -aminopterin -thymidine, or HAT medium based on the presence of a functional hypoxanthine-guanine phosphoribosyltransferase or HGPRT enzyme.
In this medium, both the HGPRT negative myeloma cells and the HGPRT positive but short-lived B cells cannot survive for long. However, the immortal hybridoma cells with the HGPRT enzyme can proliferate.
After selection, hybridoma cells that produce monoclonal antibodies with a strong affinity for the target epitope are identified and used as starter cells for establishing antibody-producing cell lines.
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Q1: What is the main purpose of hybridoma technology?
Hybridoma technology enables mass production of monoclonal antibodies that bind to a single epitope on an antigen. These antibodies are valuable in research, diagnostics, and disease therapy because they target only one specific antigenic determinant, providing high specificity and consistency for applications requiring precise immune targeting.
Q2: How are B cells and myeloma cells combined in hybridoma creation?
B cells harvested from a mouse spleen are fused with immortal myeloma cells using electric pulses (electroporation) or polyethylene glycol (PEG). This fusion creates hybrid cells called hybridomas that combine the antibody-producing ability of B cells with the unlimited growth capacity of myeloma cells, overcoming the natural limitation that B cells cannot survive long in culture.
Q3: Why is HAT medium used in hybridoma selection?
HAT medium selectively allows only hybridoma cells to survive by blocking default nucleotide synthesis. Myeloma cells lacking the HGPRT enzyme cannot use the salvage pathway and die, while short-lived B cells also perish. Only hybrid cells with functional HGPRT from B cells and immortality from myeloma cells proliferate, ensuring pure hybridoma populations for antibody production.
Q4: What happens during hybridoma screening after HAT selection?
Hybridoma cultures are plated in 96-well plates with one cell per well. Each well is screened using enzyme linked immunosorbent assay to identify cells producing antibodies specific to the target epitope. Positive cells are then grown in larger culture vessels to establish permanent hybridoma cell lines that serve as unlimited sources of monoclonal antibodies.
Q5: Why are monoclonal antibodies more useful than polyclonal antibodies?
Monoclonal antibodies bind to only a single epitope, providing high specificity and consistency. This single-target binding makes them ideal for precise research, diagnostic, and therapeutic applications where cross-reactivity must be minimized. Polyclonal antibodies, by contrast, recognize multiple epitopes and lack this specificity.
Q6: What is the significance of the HGPRT enzyme in HAT medium selection?
The HGPRT enzyme enables cells to synthesize nucleotides via the salvage pathway when aminopterin blocks the default synthesis route. Myeloma cells are HGPRT-negative and cannot survive in HAT medium, while B cells are HGPRT-positive but short-lived. Only hybridomas with functional HGPRT and immortality survive, making this enzyme critical for selecting true hybrid cells.
Q7: How does hybridoma technology overcome the limitations of natural B cells?
Natural B cells produce antibodies but have a limited lifespan and cannot be cultured indefinitely in the laboratory. Hybridoma technology fuses these cells with immortal myeloma cells, creating hybrid cells that retain antibody-producing capability while gaining unlimited growth potential. This overcomes both the finite lifespan and culture limitations of primary B cells.