FIG. 1.

Binding of soluble CEA to gonococci expressing chimeric Opa proteins. Bacteria were incubated with CEA in HEPES buffer, spun, and washed. Cell pellets were boiled, separated by SDS-PAGE, blotted onto nitrocellulose, and probed with rabbit polyclonal anti-CEA antibodies, followed by protein A-HRP. Detection was with the ECL kit from Amersham. Numbers on the left are molecular masses in kilodaltons.