Fig. 7From: Trigger factor assisted soluble expression of recombinant spike protein of porcine epidemic diarrhea virus in Escherichia coli Serum neutralizing (SN) antibody titers from mice immunized with PBS, rGST-COE and rGST-S1D. Terminal serum samples were serially diluted and subjected to the serum neutralization assay. Error bars indicate the standard deviations of the means. The asterisk indicates the p values that were less than 0.05Back to article page