(A) The map of dominant immunoreactive areas of ORF2. The amino acid residues of each area are identified. (B) The ORF2 fragment that spans from amino acid 113 to 147 was amplified with a pair of ORF2 primers (Lane 1). The entire ORF2 fragment was used as a positive control (Lane 2). The DNA marker is a 500 bp DNA ladder.