FIG. 2.

Phase-contrast and fluorescence microscopic analysis of wild-type and ΔexsY spores of B. anthracis treated with fluorescently labeled anti-BclA MAb EF12. Spores of the wild-type Sterne strain (WT) were prepared in liquid medium (A, C, E, and G), and spores of strain CLT325 (ΔexsY) were produced on solid medium (B, D, F, and H). Phase-contrast images (A and B) and fluorescence images indicating the binding of EF12 to BclA (C and D) were used to produce merged (E and F) and enlarged merged (G and H) images.