FIG. 6.

Anti-LT and anti-STa antibody neutralization. Serum and fecal samples (1:50) from rabbits immunized with pLT₁₉₂:pSTa₁₂ or pLT₁₉₂:pSTa₁₃ fusion antigen were used to neutralize purified CT (10 ng) or STa (2 ng). The mixture was added to T-84 cells to test for an increase of intracellular cGMP (for STa; an ELISA kit from Assay Design was used) or cAMP (for CT; an ELISA kit from Invitrogen was used) levels. Cell culture medium alone was included as a negative control. CT or STa toxin alone or incubated with a serum or a fecal sample from the control rabbit was also included as a negative control. Error bars indicate standard deviations.