Monoclonal antibodies recognize a single:
a. Antigen
b. Bacterium
c. Epitope
d. B cell
e. Virus
The correct answer and explanation is :
The correct answer is c. Epitope.
Explanation:
Monoclonal antibodies are laboratory-produced molecules designed to mimic the immune system’s ability to fight off harmful pathogens such as viruses and bacteria. They are created by cloning a single type of immune cell called a B cell, which produces antibodies against a specific antigen. These antibodies recognize and bind to a specific target on the antigen known as an epitope.
An epitope (also referred to as an antigenic determinant) is the specific part of an antigen that is recognized by an antibody. The antigen itself can be a part of a bacterium, virus, or other foreign substance, but the monoclonal antibody targets only a particular epitope on that antigen.
Here’s how the process works:
- B Cell Selection: First, a B cell that produces antibodies against a specific antigen is selected. In the case of monoclonal antibody production, this B cell is often obtained from an animal (commonly a mouse).
- Cloning: This B cell is then fused with a myeloma (cancer) cell, which allows the creation of a hybrid cell called a hybridoma. These hybridoma cells can divide indefinitely while producing large quantities of the specific antibody against the epitope of interest.
- Purification: The monoclonal antibodies produced by these hybridomas are harvested and purified for use in research, diagnostics, or treatment.
The key characteristic of monoclonal antibodies is that they are monospecific, meaning they bind only to one specific epitope on the target antigen. This specificity makes monoclonal antibodies very useful in various applications like targeted therapies for cancer, autoimmune diseases, and diagnostic tests for specific pathogens.
In contrast, polyclonal antibodies are mixtures of antibodies that recognize different epitopes on the same antigen, providing a broader immune response.
Why Other Options Are Incorrect:
- a. Antigen: Monoclonal antibodies are specific to a part of the antigen, the epitope, not the entire antigen.
- b. Bacterium: Monoclonal antibodies do not recognize entire bacteria, but specific molecules or epitopes on the bacteria.
- d. B cell: Monoclonal antibodies do not recognize B cells; they are designed to bind to antigens or epitopes on foreign molecules.
- e. Virus: Monoclonal antibodies do not recognize entire viruses but rather specific epitopes on viral proteins.