* For diagnosis such as in pregnancy tests
* in laboratories to measure the levels of hormones and other chemicals in blood,
or to detect pathogens
* in research to locate or identify specific molecules in a cell or tissue by binding
to them with a fluorescent dye
* to treat some diseases: for cancer the monoclonal antibody can be bound to a
radioactive substance, a toxic drug or a chemical which stops cells growing and
dividing. It delivers the substance to the cancer cells without harming other cells
in the body.
* A hormone called HCG is found in the urine of pregnant women
* Pregnancy testing sticks detect this hormone. This is how they work:
* The bit of the stick you wee on has some antibodies to the HCG hormone with
blue beads attached.
* The test strip (which turns blue if you are pregnant) has some more antibodies
to the hormone stuck on to it, so they can’t move.
* The HCG hormone binds to the antibodies on the bit of the stick where you wee
and the antibodies on the test strip.
If you’re pregnant and you wee on the stick:
* The HCG hormone binds to the antibodies attached to the blue beads.
* The urine moves up the stick carrying the HCG hormone and the blue beads
with it.
* The blue beads and HCG hormone bind to the antibodies on the test strip –
so the antibodies get stuck on the test strip turning it blue – showing you
are pregnant.
If you’re not pregnant and you wee on the stick:
* The urine still moves up the stick carrying the blue beads. * But because there is no HCG hormone to bind to the antibodies on the test strip it doesn’t go blue.
