FIG. 6.
Comparison of anti-LPS and anti-RFBL antibodies in the serum of mice immunized with WR201. Animals were immunized intraperitoneally 9 weeks previously then challenged intranasally with 16M. Sera were collected from mice 1 to 14 days after challenge and were analyzed by ELISA for antibody to LPS or lysate of rough B. melitensis. OD units represent the dilution of serum required to give an A410 of 0.5 (approximately the half-maximal value of the OD-serum dilution curve). The regression line formula and correlation coefficient were determined by the least-squares method.