Table 3.
Results of iodination of cetuximab with addition of HEPES and/or lactose and iodination of BoNT-A
| Product (50 μg) | HEPES (μmol) | Lactose (mg) | IODOGEN (μg) | 125 I (MBq) | Labelling efficiency (%) | 125 I/product molar ratio |
|---|---|---|---|---|---|---|
| Cetuximab | 0 | 0 | 2.5 | 19.6 | 80.7 | 0.59 |
| Cetuximab | 0 | 0.625 | 2.5 | 19.3 | 78.3 | 0.56 |
| Cetuximab | 1 | 0 | 2.5 | 15.7 | 43.5 | 0.25 |
| Cetuximab | 1 | 0.625 | 2.5 | 30.2 | 43.5 | 0.49 |
| Cetuximab | 1 | 0.625 | 1.25 + 1.25 | 15.6 | 50.2 | 0.29 |
| Cetuximab | 1 | 0.625 | 1.25 + 1.25 | 93.4 | 51.8 | 1.80 |
| Cetuximab | 1 | 0.625 | 1.25 + 1.25 | 146.2 | 43.0 | 2.34 |
| BoNT-A | -a | -a | 1.25 + 1.25 | 97.2 | 51.5 | 1.86 |
| BoNT-A | -a | -a | 1.25 + 1.25 | 98.3 | 51.8 | 1.90 |
Conditions: 2.5 μg IODOGEN in 35 μL IODOGEN/acetonitrile added at t = 0 or 1.25 μg IODOGEN in 17.5 μL IODOGEN/acetonitrile added at t = 0 and at t = 45. Other conditions: 250 μL reaction volume and 90-s reaction time. Radiochemical purity was >98.5% in all experiments.
aReconstituted BoNT-A contained HEPES (20 mM) and lactose (1.25%); this was not purposely added.