DOI:
ABSTRACT
The methods of limited periodate oxidation and reductive amination were used to obtain covalently linked enterobacterial common antigen (ECA) with tetanus toxoid. This procedure is simple and gives a good yield of the conjugate with high ECA content (molecular ratio of ECA to tetanus toxoid, 6:1). The ECA-tetanus toxoid conjugate is immunogenic in rabbits, in contrast to free ECA or a mixture of ECA with proteins. This conjugate produces high levels of ECA-specific immunoglobulin G antibodies, which can be used as a standard serum.