Detection of gum from Acacia seyal and species of combretum in admixtures with A. senegal Using monoclonal antibodies

Abstract

Monodonal antibody immunoassays have been developed for the detection of gum from Acacia seyal and combretum gum in commercial gum arabic (A. senegal). Eight hybridoma celt lines were raised to gum from A. seyal that secrete monoclonal antibodies (MAbs) that recognize, by ELISA, gum from A. seyal but not gum from A. senegal; one of these antibodies (SY JIA1) also recognizes combretum gum. All the antibodies belong to the immunoglobutin class IgM. Plate trapped antigen-ELISA (PTA-ELISA) tests of heat, periodate, pronase and trypsin treated gums indicate that they all recognize heat stable carbohydrate epitopes. Two of these MAbs, SY HH3 and SY JIA1, have been identified as suitable for the detection of gum from A. seyal or combretum gum, in mixtures with gum from A. senegal. The limit of detection of seyal gum in mixtures using SY HH3 in PTA-ELISAs was 0.5% and the limit of detection of combretum gum in mixtures using SY JIA1 in competition ELISAs was 0.1%. The sensitivity of these immunoassays for the gum from A. seyal or combretum gum in mixtures is 10 to 100 times greater than any of the procedures currently in use.