FIG. 3.

Agarose gel analysis of PT4 and STM7 primer sets used to discriminate paired serotypes. The template DNA used is indicated above each lane, as are primer sets. The sizes of DNA standards are indicated to the left of the gel in base pairs. S. enterica serovar Enteriditis yields the expected 225-bp amplicon, and S. enterica serovar Dublin does not. The 101-bp amplicon is produced only with S. enterica serovars Saintpaul and Braenderup DNA and not with S. enterica serovar Anatum or Ohio DNA.