How It Works: From Hybridoma Cell to Medical Test
Part of Monoclonal Antibodies — GCSE Biology
This how it works covers How It Works: From Hybridoma Cell to Medical Test within Monoclonal Antibodies for GCSE Biology. Production and medical applications of identical antibodies, hybridoma cells, diagnostics It is section 10 of 17 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 10 of 17
Practice
15 questions
Recall
18 flashcards
How It Works: From Hybridoma Cell to Medical Test
The key challenge in producing monoclonal antibodies is that the B cells which naturally produce specific antibodies cannot survive long in laboratory culture — they die within days. The solution, discovered by Kohler and Milstein in 1975, was to fuse B cells with myeloma (cancer) cells to create hybridoma cells that combine the antibody-producing ability of B cells with the immortality of cancer cells.
The production process exploits the immune system's own specificity. A mouse is immunised with the target antigen — for example, a specific cancer cell surface protein. The mouse's immune system produces B cells that make antibodies against this antigen. These B cells are extracted from the mouse's spleen and fused with myeloma cells using a chemical agent or electric pulse. The resulting hybridoma cells can divide indefinitely and produce the specific antibody against the original antigen in unlimited quantities.
In a pregnancy test, this principle is applied elegantly: the test strip contains two types of monoclonal antibodies. Free-floating antibodies (in the conjugate pad) are specific to hCG (human chorionic gonadotropin — a hormone only present if pregnant) and are attached to coloured particles. Immobilised antibodies (in the test line) are also specific to hCG. If hCG is present in the urine, it binds to the free antibodies, which then travel along the strip and are captured by the immobilised antibodies, producing a coloured line. The control line confirms the test worked correctly. This is a lateral flow immunoassay — fast, cheap, and highly specific.
For cancer treatment, the same specificity is exploited in a different way: antibodies specific to cancer cell surface proteins are given to a patient. They travel through the blood, find cells displaying those proteins, and bind to them. This can directly flag the cells for destruction by the immune system, block receptor signals that cancer cells use to grow, or deliver toxic drugs or radioactive atoms directly and selectively to cancer cells.