FIG. 2.

MAb F26G4 produces a capsule reaction only with an inner capsular layer, whereas MAb 21Bl produces a capsule reaction with only the outer capsular layer. Sequential addition of MAbs produces a reaction with both layers. Top row: left, DIC image in the absence of antibody; center, capsule reaction produced by MAb F26G4 alone (100 μg/ml); right, capsule reaction produced by MAb 21Bl alone (100 μg/ml). Bottom rows: images of three cells incubated with MAb F26G4 followed by MAb 21Bl (100 μg/ml each).