Fig. 1

Cloning, expression and purification of the PEDV spike protein. a PCR amplification of the truncated spike gene of PEDV corresponding to the 1330–2310 bp of the spike protein gene (444–770 amino acids). Lanes 1–2, PCR amplification products of the PEDV spike gene. b SDS-PAGE analysis of the expression and purification of the PEDV spike protein. Lanes 1–2, the supernatant of E. coli cell lysate that were transformed with the PEDV spike protein gene after induction. Lanes 3–4, PEDV spike protein eluted from Ni–NTA Agarose. c Western blot analysis of the PEDV spike protein with an anti-6× His antibody. Lanes 1–2, the purified PEDV spike protein. Lane M, molecular weight marker