ELISA analysis was performed using Sheep IgG h+l antigen (500 ng/well, 60 min). Samples were blocked for 60 min with 1% BSA, incubated with Sheep IgG h+l (60 min), and followed by HRP Goat anti-Rabbit IgG h+l (Product # SA5-10311) for 30 min. Development was done with TMB substrate (10 min) and the reaction was stopped with 0.3M H2SO4. Results were read on a microplate reader at OD450.