FIG 6.
Competitive STa ELISAs to measure guanylin and uroguanylin cross-reactivity with anti-STa antibodies in serum samples of mice immunized s.c. with the 3×STaL9A/N12S-mnLTR192G/L211A, 3×STaN12S/A14T-mnLTR192G/L211A, 3×STaL9A/N12S/A14H-mnLTR192G/L211A, or 3×STaL9A/A14H-mnLTR192G/L211A fusion protein. PBS, 50 ng STa toxin, 50 ng guanylin, or 50 ng uroguanylin mixed with serum dilutions from each immunization group was added to wells of competitive STa ELISA plates. The OD405 was measured and converted to a percentage to indicate antibody reactivity, with the OD in the wells incubated with a 1:1,000 dilution of mouse serum and PBS having a value of 100% (0% antibody cross-reactivity).