2.8. Measurement of serum IgE
Blood was obtained from tail vein of mouse at 2 weeks (to check disease induction) and at the end of 4 weeks (to check effect of PE treatment on disease progression). Total serum IgE was measured by ELISA kit (BD Biosciences) with serum diluted 200-fold. Detection antibody and streptavidin conjugated HRP were diluted 500 or 250-fold, respectively and absorbance was measured at 490 nm. Serum total IgE concentration of each sample was determined from a standard curve of mouse IgE.