Et monoklonalt antistof er en type protein, der er opbygget, så det binder sig til en bestemt struktur, der kaldes et antigen og findes på overfladen af visse celler i organismen.
A monoclonal antibody is an antibody (a type of protein) that has been designed to recognise and bind to a specific structure (called an antigen) that is found on the surface of cells in the body.