CA19-9, a carbohydrate epitope expressed on a high MW (>400kDa) mucin glycoprotein, is a sialyl Lewisa structure which is synthesized from type 1 blood group precursor chains and is present in individuals expressing the Lewisa and/or Lewisb blood group antigens.

Store the recombinant CA19-9 antibody at 2-8°C (with azide) or aliquot and store at -20°C or colder (without azide).