| Xanthine, [8-14C]-....Freeze dried solid | MC 181 |
| Xanthine, [8-14C]-....0.01N NH4OH under argon, 100 �Ci/ml | MC 181A |
| Xanthine, [8-3H]- | MT 537 |
| Xanthosine, [8-14C]- | MC 178 |
| Xanthosine, [8-3H]- | MT 536 |
| Xanthosine 5'-monophosphate, diammonium salt, [8-14C]- | MC 182 |
| Xanthurenic acid sodium, [3H]- | MT 1853 |
| o-Xylene, [methyl-3H]- | MT 1582 |
| D-Xylose, [14C(U)]- Discontinued | MC 1140 |
| D-Xylose, [1-14C]- | MC 2151 |
| Zanamivir hydrate | M 1826 |
| Zanamivir hydrate, [3H]- | MT 1843 |
| Zearalenone, [3H]- | MT 1955 |
| trans-Zeatin, [3H]- | MT 1977 |
| Zebularine, [2-14C]- | MC 242 |
| Zebularine, [5'-3H]- | MT 1863 |
| Zebularine, [5'-3H]- | MT 1863L |
| Zoledronic acid | M 1875 |
| Zoledronic acid, [3H]- | MT 2044 |