Figure 3: Serum response. Serum was collected 1 week after final vaccination and analyzed for M2e-specific serum IgG by ELISA using microtiter plates coated with 2 μg/mL M2e peptide. The plates were developed with goat antichicken IgG-horseradish peroxidase conjugate and chemiluminescent substrate. Luminescent signal from each sample was converted to concentration of chicken IgG by extrapolation from the graph of luminescence versus IgG concentration of the standards and corrected for sample dilution. Each sample was analyzed at two or three different dilutions, and each dilution was analyzed in duplicate. Group mean M2e-specific IgG concentration is shown.