Haptenic relationships of p-azobenzenesulfonate and some structurally-related food dyes

Abstract

Tartrazine, an FD&C approved azo dye, has been implicated in food and drug-borne allergic reactions. The dye was coupled to bovine serum albumin (BSA) by a water-soluble carbodiimide and by bis-diazotized benzidine. Both conjugates, as immunogens in rabbits, elicited the production of antibodies specific for tartrazine. The antibodies cross-reacted with other FD&C dyes, the extent of the reaction depending on the structural relationship of these dyes to tartrazine. Tartrazine is structurally and haptenically related to p-azobenzenesulfonate. Antibodies to tartrazine, however, are serologically unique. The tartrazine-BSA conjugates should be useful in skin-test studies for tartrazine allergies and in immunoassays for the dye.