Monoclonal antibodies hybridoma-derived

Monoclonal antibodies are derived from a single, monospecific B cell clone. Monoclonal antibodies can be obtained from hybridoma cells that result from the fusion of antibody-producing B cells with immortal cells of a myeloma cell line. 

Monoclonal antibody, mAb Describes an antibody derived from a single clone of cells or a clonally obtained cell line. Its common use denotes an antibody secreted by a hybridoma cell line. Monoclonal antibodies are used very widely in the study of antigens, and as diagnostics. 

Cell Fusion Unlike antibody-secreting cells, myeloma cells, malignant tumor cells of the immune system, can be cultured continuously. Kohler and Milstein (1975) developed a method to fuse (hybridize) B-lymphocytes from the mouse spleen with mouse myeloma cells, so that the fused cell, hybrid-myeloma (or hybridoma) cell, can have the characteristic of the both cell lines that is, the production of specific antibodies and the immortality. Since the hybridoma is derived from a single B-lymphocyte, it produces only one kind of antibody, thus a monoclonal antibody. 

Monoclonal antibodies are produced as a result of immortalizing and expanding the individual antibody secreting cells artificially in tissue culture (2). Cells grown in this way all have identical epitope specificity and because they are derived from single clones, their product is known as monoclonal antibody. Cells that secrete monoclonal antibodies are known as hybridomas and are typically derived by fusion of two cell types. B-lymphocytes, which have the capacity to make antibody, are obtained from a donor spleen and are physically fused to a tumor cell line, which is immortal. The resulting hybridom as are immortal and produce antibody into the synthetic medium in which they are growing. 

Hybridomas are derived from the fusion of spleen and myeloma cells and produce monoclonal antibodies. Each hybridoma cell line produces an antibody with a unique specificity allowing the production of highly defined reagents that can be used in many branches of immunochemistry. 

In 1975, Kohler and Milstein reported (1) that immortal cell lines secreting antibody of a single specificity could be produced by the artificial fusion of splenocytes derived from an immune mouse and tumour cells derived from a murine myeloma. They called these cell lines hybridomas and the product from them monoclonal antibodies. The development of monoclonal antibodies opened up huge possibilities in all areas of antibody use because reagents could be created with specificity to a single domain (epitope) on the target... 

Other species of hybridomas, including human, have been produced but are generally created by the use of viruses conferring cellular immortality. Artificial immunization of the donor is often not practical or ethical and so cell lines are often derived from peripheral lymphocytes obtained from individuals naturally immune to the target substance. Some human monoclonal antibody secreting cell lines have been derived from spontaneously occurring myelomas, but this line of approach frequently is unrewarding as the probability that the antibody will be one of interest is remote. 

The problem is that if an individual antibody-producing cell is isolated and grown in culture, its descendants have a limited lifespan that severely limits their use for the routine preparation of monoclonal antibodies. In 1975, Milstein and Kohler discovered how monoclonal antibodies of almost any desired antigen specificity can be produced indefinitely and in large quantities. Their method was to fuse a B lymphocyte producing antibody of the desired specificity with a cell derived from a cancerous lymphocyte tumor, called a myeloma cell, which is immortal. The cell fusion is called a hybridoma, which is both immortal and secretes the same specific antibody originally encoded by the B lymphocyte. 

ELISA, you will determine the titer of this antibody, as well as that of a monoclonal antibody against /3-galactosidase, called J1, that is derived from a mouse hybridoma cell line. Based on the titer of the J1 antibody, you will perform a competitive ELISA to determine the concentration of /3-galactosidase in an unknown solution. 

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