FIG 1.

SDS-PAGE and Western blots of the five candidate vaccine proteins. The five candidate proteins were expressed in E. coli and purified as described in Materials and Methods. The purified proteins were run on an SDS-polyacrylamide gel (A) and also transferred to membranes and probed with either serum from a pig experimentally infected with S. suis serotype 2 (B) or sera from pigs raised in a pathogen-free environment as a negative control (C). The numbers on the left are molecular masses (in kilodaltons).