Table 2. Comparison of the SPR assay and the mouse bioassay for serum sample analysis.
| Estimated LD50/mouse | SPR assay mAb bound (RU) | Mouse bioassay (n° of deaths/total n° of mice) |
|---|---|---|
| 5 | 366.0 ± 9.4 (n = 1) | 9/9 |
| 1 | 156.6 ± 28.9 (n = 3) | 8/13 |
| 0.5 | 89.6 ± 12.4 (n = 3) | 0/5 |
| 0.25 | 54.7 ± 6.8 (n = 2) | ND |
| 0.125 | 20.7 ± 8.0 (n = 2) | ND |
| 0 | 1.6 ± 2.5 (n = 3) | ND |
BoNT/E was diluted in serum and aliquoted before in vitro and in vivo measurements. SPR experiments were repeated independently 2 or 3 times for BoNT/E concentrations =1 LD50/ml after 10 fold dilution in different sera (LOD value = 9.2 RU). Mice were observed for 4 days. ND, not done.