Figure 4.

Serum PoC3 binding to bacteria. (A) Different bacteria were incubated with or without (control) serum for 1 h, and Western blot was performed to detect bacteria-bound serum C3 with mouse anti-PoC3 polyclonal antibody. Lane 1, Japanese flounder serum. Lane 2, protein marker. Lane 3 to 8 are Vibrio harveyi, Edwardsiella tarda, Escherichia coli, Streptococcus iniae, Vibrio anguillarum and Pseudomonas fluorescens. (B) Different bacteria were incubated with or without different dilutions fold Japanese flounder serum, and PoC3 in serum interacted with bacteria was determined by ELISA. Data are the means of three independent assays and presented as means ± SEM.