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It might be worth explaining a bit more about how antibodies are made. There are these cells called B lymphocytes, whose job is to produce antibodies. When they form, they randomise parts of the antibody genes: https://en.wikipedia.org/wiki/V%28D%29J_recombination As a result, every B lymphocyte makes one particular antibody that is different to every other B lymphocyte, and which recognises a different molecular pattern to every other B lymphocyte. There's a process in their development which weeds out cells which recognises patterns in your own body, leaving a population of cells which (hopefully) recognise every possible pattern which is not part of your own body. B lymphocytes then wander round the body, looking for stuff which binds to their antibody; if they find it, they know it must be an invader, and they raise the alarm, triggering an immune response (subject to checks and balances from other parts of the immune system). As part of that, the cell which raised the alarm will proliferate, making millions of cells producing identical antibodies, which bind to the invader and mark it for destruction by other cells of the immune system. If an invader has more than one molecular pattern (which it will - every patch on the surface of a protein is a pattern, and a bacterium will have all sorts of proteins and other things on its surface), then a corresponding number of B lymphocytes should recognise it, and proliferate in response. So, if you insult a rabbit with your protein, you will activate all the B lymphocytes which recognise patterns on it. If you purify antibodies from its bloodstream, you will get antibodies recognising all those patterns - and any other antibodies which happen to be in the bloodstream at the time. If you isolate a single B lymphocyte its bloodstream, make it immortal, culture it, and purify the antibodies from that, you will get a single kind of antibody, recognising a single molecular pattern. In software terms, a monoclonal is a bit like detecting spam by grepping for a single spam-specific word, and a polyclonal is a bit like doing an n-gram comparison with a corpus of known spam. |