The invention relates to a seal for at least one bipolar plate (20) of a fuel cell (10), consisting at least partially of a sealing material which is suitable for sealing medium flows in the fuel cell (10). At least one structure (30) conducting a reaction medium is integrated in the seal (28), and the reaction media can be conducted to and/or away from the bipolar plate (20) via said structure. An assembly comprising a bipolar plate (20) and a seal (28) can be produced by temporarily expanding the seal (28) and inserting the bipolar plate (20) into the seal (28) during said temporary expansion. Alternatively, the seal (28) can be moulded onto the bipolar plate (20).
