Preparation and Immunological Properties of a Brilliant Blue-Protein Conjugate

Abstract

Brilliant Blue F.C.F. (BB), after purification to remove high molecular weight, blue-colored contaminants present in commercial preparations, was conjugated to bovine serum albumin (BSA). Phosphorus oxychloride was used to transform the sulfonate groups of BB to sulfonyl chloride groups; the product of this reaction was then allowed to react further with the protein. The conjugate thus prepared was purified by Sephadex G-25 column chromatography and found to contain 7 moles of BB per mole of BSA. Immunological studies in the rat indicated that neither IgE nor IgGa antibodies to BB could be detected in the sera of immunized animals. This would tend to suggest that BB possesses a low degree of allergenicity. However the possibility that some individuals under appropriate circumstances could respond with allergic manifestations to BB cannot be dismissed.