Affinity purified antibodies of polyclonal rabbit antiserum to plasminogen from human plasma. This product is intended for use in precipitating and non-precipitating antibody-binding assays (such as e.g., ELISA and Western blotting and immuno-fluorescence or histochemical techniques); to prepare an insoluble immuno-affinity adsorbent; for labelling with a marker of the customer's own choice.