ABSTRACTBovine β-lactoglobulin (BLG) is one of the major allergens in cow’s milk. Epitopes play a key role in food allergy, while most of the antibodies developed do not specifically recognize the IgE-binding epitopes. Here, a tandem derived from human IgE linear epitopes of BLG (tBLG) was designed according to the principles of epitope-based vaccine methodology, expressed in Escherichia coli, and a polyclonal antibody (pAb-tBLG) was developed. The recombinant tBLG protein preserved the antigenicity and potential allergenicity of epitopes. The pAb-tBLG recognized all the IgE epitopes of tBLG, and showed a high specificity, but it had weak cross-reactivity with caseins. We concluded that pAb-tBLG can detect of BLG and may be useful for identifying allergenic residues in dairy products.