Fig. 5

Titer of IgG1 and IgG2a isotypes against OMP31 protein. a the titer comparison of IgG1 and IgG2a isotypes related to 1/50 dilution of sera against OMP31 protein. Mean comparison of treatments, with significance level of 0.05, were carried out using Tukey’s test. b Ratio of IgG2a to IgG1 in different treatments. Levels of each antibody were measured at OD 405 nm by an ELISA reader. Each value represents the mean of triplicates ± SD of antibody responses from five samples. The experiment was replicated three times. Different letters refer to significantly variations between experimental groups (P < .05)