Hybridoma Technology is used to produce? (GATE BT 2010)
|a) Monoclonal Antibodies||b) Polyclonal Antibodies|
|c) Both Monoclonal and Polyclonal||d) B Cells|
Correct Answer is: Monoclonal Antibodies.
Hybridoma technology, discovered by G.Kohler and C.Milstein(1975) refers to a technique wherein Hybrid Cells are produced by fusion of B-lymphocytes with tumour cells (Somatic Cell Fusion). The hybrid cells so produced have the ability to produce ‘specific’ antibodies (contributed by B-lymphocyte genetic material) as well as indefinite dividing capacity in the culture owing to the presence of tumour cell or myeloma cells in hybrid generation. The B-lymphocytes used in Hybrid generation are pre-programmed to respond to a single type of antigen or antigenic determinant, thereby producing a single type of antibody specific to the specific antigen, referred to as Monoclonal Antibodies.
G.Kohler and C.Milstein received Nobel Prize in Physiology and Medicine along with N.Jeme in 1984, for their ground breaking discovery of Hybridoma Technology.
(Image source: en.wikipedia.org)
Monoclonal antibodies (mAb or moAb) are monospecific antibodies that are the same because they are made by identical immune cells that are all clones of a unique parent cell, in contrast to polyclonal antibodies which are made from several different immune cells. Monoclonal antibodies have monovalent affinity, in that they bind to the same epitope.
Some interesting facts about the process:
The cell fusion mixture is transferred to a culture medium — called HAT medium because it contains:
The pyrimidine thymidine
Unfused myeloma cells cannot grow because they lack HGPRT.
Unfused normal spleen cells cannot grow indefinitely because of their limited life span. However,
Hybridoma cells (produced by successful fusions) are able to grow indefinitely because the spleen cell partner supplies HGPRT and the myeloma partner is immortal.
2. Test the supernatants from each culture to find those producing the desired antibody.
3. Because the original cultures may have been started with more than one hybridoma cell, you must now isolate single cells from each antibody-positive culture and subculture them.
4. Again, test each supernatant for the desired antibodies. Each positive subculture — having been started from a single cell — represents a clone and its antibodies are monoclonal. That is, each culture secretes a single kind of antibody molecule directed against a single determinant on a preselected antigen.
5. Scale up the size of the cultures of the successful clones.
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