- ?Lv 51 decade agoFavorite Answer
Rituximab is a chimeric monoclonal antibody. Monoclonal antibodies are monospecific antibodies that are identical because they are produced by one type of immune cell that are all clones of a single parent cell. Given (almost) any substance, it is possible to create monoclonal antibodies that specifically bind to that substance; they can then serve to detect or purify that substance.
1. Hybridoma Cell Production
Monoclonal antibodies are typically made by fusing myeloma cells with the spleen cells from a mouse that has been immunized with the desired antigen. However, recent advances have allowed the use of rabbit B-cells. Polyethylene glycol is used to fuse adjacent plasma membranes, but the success rate is low so a selective medium is used in which only fused cells can grow. This is because myeloma cells have lost the ability to synthesize hypoxanthine-guanine-phosphoribosyl transferase (HGPRT), an enzyme necessary for the salvage synthesis of nucleic acids.
This mixture of cells is then diluted and clones are grown from single parent cells on microtitre wells. The antibodies secreted by the different clones are then tested for their ability to bind to the antigen (for example with a test such as ELISA or Antigen Microarray Assay) or immuno-dot blot, and the most productive and stable clone is then grown in culture medium to a high volume.
2. Purification of Monoclonal Antibodies
After obtaining either a media sample of cultured hybridomas or a sample of ascites fluid, the desired antibodies must be extracted.
The production of recombinant monoclonal antibodies involves technologies, referred to as repertoire cloning or phage display/yeast display.