Monoclonal antibodies and their uses
Biology · GCSE · The School
One antibody, made identically, many times over
A MONOCLONAL antibody is a single type of antibody. It comes from identical cells, all targeting one specific antigen. A natural infection is different. It produces a mixture of antibodies, from many white blood cells, each recognising a slightly different part of the pathogen.
How they are made
A mouse is injected with the target antigen. Its white blood cells then produce antibodies against it. Those cells cannot divide forever alone. So they are fused with a fast-dividing tumour cell, making a HYBRIDOMA cell. It can both make the right antibody AND keep dividing. Hybridomas are cloned, producing large quantities of one identical antibody.
Why specificity is the whole point
A monoclonal antibody binds to ONE specific antigen, and nothing else. So it can find, block, or deliver something to exactly one target. A specific hormone. A specific protein on a cancer cell. Everything else is left alone. That precision is what sets it apart from most other medical treatments.
A worked example: a pregnancy test
A pregnancy test strip holds monoclonal antibodies, bound to a dye. They bind specifically to hCG, a hormone in a pregnant person's urine. If hCG is present, it binds the antibody. This triggers a colour change at the test line. If hCG is absent, nothing binds, and the line stays blank. That specificity is why the test ignores other hormones in the urine.
Uses beyond a pregnancy test
In cancer treatment, a monoclonal antibody can be built to bind antigens on cancer cells. It might block a growth signal directly. Or it might carry a toxic drug straight to the tumour, sparing healthy cells. In diagnosis, antibodies can detect specific molecules to identify a disease. In research, they locate or measure specific molecules in a sample.
The limitation worth naming
Making monoclonal antibodies is more complex and costly than many other treatments. Some patients get side effects too. The antibody is specific, but the immune system can still react to it as a foreign substance. An answer that only lists benefits, with no limitation, reads as one-sided — even when every benefit listed is true.