Identify the organism or tissue involved
Antigens are initially used in the process and artificial antibodies are produced.
Antigens are any substance that is foreign to an organism’s own body.
Antibodies are specific; they bind to and attack one particular antigen. Some antibodies, once activated by the occurrence of a disease, continue to confer resistance against that disease.
Details of the process used
1. A mouse is immunized by injection of an antigen to stimulate the production of antibodies targeted against the specific antigen.
2. Antibodies are produced by the mouse in the spleen. After several weeks of immunisation, blood samples are obtained for measurement of serum antibodies in the mouse. If the amount of antibodies present is high, then cell fusion can be performed. If the amount of antibodies is too low, the mouse can be boosted until an adequate amount of antibodies are produced.
3. Mouse is euthanized, spleen is removed and antibody forming (B-Lymphocyte) cells are isolated from the mouse's spleen.
4. The antibody forming cells and the malignant tumour cells called myelomas are then fused together with a chemical, polyethylene glycol, which disrupts cell membranes and allows the two cells to fuse. The resulting hybrid cell is able to grow on a specific medium in which neither the spleen cells nor the pure myeloma cells can grow. The hybrid cell will possess the property of the immortal character of the tumour cell and the specific antibody production.
5. The hybridomas are then screened for antibody production. Those that function properly are grown in a culture. Each hybridoma produces relatively large quantities of identical antibody molecules. By allowing the hybridoma to multiply in culture, it is possible to produce a population of cells, each of which produces identical antibody molecules. These antibodies are called "monoclonal antibodies" because they are produced by the identical offspring of a single, cloned antibody producing cell.
6. The hybridoma and their clones can be injected into another mouse where the ascites fluid which contains monoclonal antibodies is harvested from the mouse (in vivo) or they can be they can be grown in mass culture to produce specific antibodies (in vitro).
Describe the outcome of the biotechnological process
Monoclonal antibodies can be used:
In measuring protein and drug levels in serum
To protect against disease
To diagnose a wide variety of illnesses
To detect the presence of drugs, viral and bacterial products, and other unusual or abnormal substances in the blood
To detect a variety of diseases such as breast and prostate cancer.
In home pregnancy kits – antibodies present in the kit reacts with a hormone secreted by an embryo and present in the mother’s urine.
To treat cancer, bacterial poisoning and snake bite.
Some examples of monoclonal antibodies in common use are:
OKT3 – binds to a molecule on the surface of T cells in order to prevent acute rejection of organs.
Herceptin – binds to a receptor for epidermal growth factor that is found on some tumour cells. It is effective against solid tumours.
Abciximab - Inhibits the clumping of platelets by binding the receptors on their surface. Helpful in preventing re-clogging of the coronary arteries in patients who have undergone angioplasty.
Evaluate the efficiency of the process
At the moment, the processes used to obtain Monoclonal antibodies rely heavily on the use of