The later was conjugated as hapten to BSA or OVA by the mixed anhydride method, for animal immunization and coating plates respectively.

• 用混合酸酐法通过半抗原上的羧基与牛血清蛋白（BSA）和鸡卵清白蛋白（OVA）上的氨基反应，从而合成DES人工免疫原与包被原。