What are monoclonal antibodies?

Monoclonal antibodies are indeed antibodies that are produced by identical immune cells cloned from a unique parent cell. This process involves creating a hybridoma, which is formed by fusing a specific type of immune cell that produces antibodies (B-cells) with a myeloma (cancer) cell that can divide indefinitely. The result is a cell line that can produce large quantities of a single type of antibody, hence the term "monoclonal." This specificity allows these antibodies to target specific antigens, making them invaluable in diagnostic procedures, treatment of diseases such as cancer, and therapeutic applications.

The other options provide different contexts that do not accurately define monoclonal antibodies. Antibodies produced by multiple immune cells refer to polyclonal antibodies, which are a mixture of antibodies that recognize different epitopes on the same or different antigens, and this does not describe the uniformity of monoclonal antibodies. The mention of proteins synthesized from various strains of bacteria pertains to recombinant proteins and does not describe the antibody structure or formation. Lastly, enzymes that assist in DNA replication, such as DNA polymerases, are a separate category of biological molecules not related to antibodies at all. Understanding the specific origin and production method of monoclonal antibodies