Figure 5. Recognition of plate bound and soluble ricin by RTB-B7.

(A) ELISA plates were coated overnight with ricin. Antibodies 24B11 and V_HHs were serial diluted and added to the coated plates and developed as described in Materials and Methods. Shown on the Y-axis is optical density (OD). (B) For the competition ELISA, plates were coated with ricin overnight. Ricin (200 µg/mL) was serial diluted and pre-mixed with constant concentration of the indicated antibodies at equal molar amounts taking into account the number of binding sites (V_HHs at 10 µg/mL and 24B11 at 22.75 µg/mL). Ricin:Ab solutions were then added to the plates and developed. The data shown represent a single experiment in which each sample was done in triplicate and repeated at least twice. Data are expressed as the mean ± SD.