DETECTION OF GUM FROM ACACIA SEYAL AND SPECIES OF COMBRETUM IN ADMIXTURES WITH ACACIA-SENEGAL USING MONOCLONAL-ANTIBODIES

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 cell lines were raised to gum from A. seya l that secrete monoclonal antibodies (MAbs) that recognize, by ELISA, gum from A. seyal but not gum from A. senegal; one of these antibodies (SY JIAl) also recognizes combretum gum. All the antibodies belong to the immunoglobulin class IgM. Plate trapped antigen-ELISA (PTA-ELISA) tests of heat, periodate, pronase and trypsin treated gums indicate t hat they all recognize heat stable carbohydrate epitopes. Two Of these MAbs, SY HH3 and SY JIAl, have been identified as suitable for the de tection of gum from A. seyal or combretum gum, in mixtures with gum fr om A. senegal. The limit of detection of seyal gum in mixtures using S Y HH3 in PTA-ELISAs was 0.5% and the limit of detection of combretum g um in mixtures using SY JIAl in competition ELISAs was 0.1%. The sensi tivity of these immunoassays for the gum fi-om A. seyal or combretum g um in mixtures is IO to 100 times greater than any of the procedures c urrently in use.