Monoclonal Antibodies Are Identical and Highly Specific

1. Monoclonal antibodies are made from a single clone of identical cells, so every antibody molecule is exactly the same.
2. Each one binds to one binding site on one antigen.
3. This makes them extremely specific, so they can target a single chemical or a single type of cell in the body.
4. Because huge numbers of identical antibodies can be made, they are very useful in medicine and research.

Step 1: A Mouse Makes the Antibody-Producing Lymphocytes

1. A mouse is injected with the antigen that the wanted antibody must bind to.
2. The mouse's lymphocytes respond by making the specific antibody.
3. These lymphocytes are then collected from the mouse.
4. On their own, lymphocytes make the antibody but cannot divide enough to make useful quantities.

Step 2: Lymphocytes Are Fused With Tumour Cells to Form Hybridomas

1. Each lymphocyte is fused with a tumour cell.
2. Tumour cells divide rapidly and keep dividing again and again.
3. The fused cell is a hybridoma, which can both make the antibody (from the lymphocyte) and divide rapidly (from the tumour cell).

Step 3: Cloning the Hybridoma Makes Large Amounts of Pure Antibody

1. A single hybridoma is cloned to make many identical cells.
2. All of these cells produce the same antibody.
3. The antibody is collected and purified, and because it comes from one clone it is called a monoclonal antibody.