| Uracil, [2-13C, 1,3-15N2]- | MG 129 |
| Uracil, [14C(U)]- | MC 281 |
| Uracil, [2-14C]- | MC 124 |
| Uracil, [6-14C]- | MC 159 |
| Uracil, [5-3H]- (> 10 Ci/mmol, Aqueous solution) | MT 610 |
| Uracil, [5-3H]- (5-10 Ci/mmol, Aqueous solution) | MT 610M |
| Uracil, [5,6-3H]- (40-60 Ci/mmol) | MT 512 |
| Uracil, [5,6-3H]- (10-39 Ci/mmol) | MT 512L |
| Uracil, [6-3H]- | MT 656 |
| Uracil-β-D-arabinofuranoside, [2-14C]- | MC 241 |
| Uracil-β-D-arabinofuranoside, [5'-3H]- | MT 818 |
| Uracil-β-D-arabinofuranoside, [5,6-3H]- | MT 705 |
| Uracil-β-D-arabinofuranoside-5' monophosphate, diammonium salt | M 997 |
| Uracil-β-D-arabinofuranoside-5' monophosphate, diammonium salt, [5-3H]- | MT 997 |
| URB-597, [cyclohexyl-3H]- | MT 2139 |
| Urea, [14C]- | MC 141 |
| Urea, [13C, 15N2]- | MG 142 |
| Uric acid, [8-14C]- | MC 1394 |
| β-L-Uridine | M 321 |
| Uridine, [14C(U)]- Discontinued | MC 287 |
| Uridine, [2-14C]- | MC 105 |
| Uridine, [5-3H]- | MT 602 |
| Uridine, [5-3H]- | MT 602E |
| Uridine, [5'-3H]- | MT 784 |
| Uridine, [5,6-3H]- Discontinued | MT 799 |
| Uridine, [5,6-3H]- | MT 799M |
| Uridine, [6-3H]- Discontinued | MT 505 |
| L-Uridine, [3H]- | MT 1694 |
| Uridine diphosphate galactose, [galactose-14C(U)]- Discontinued | MC 1116 |
| Uridine diphosphate-D-glucose, [D-glucose-14C(U)]- Discontinued | MC 2709 |
| Uridine diphosphate-D-glucose, diammonium salt, [D-glucose-14C(U)]- Discontinued | MC 184 |
| Uridine 5'-diphospho-N-acetyl-D-glucosamine, [acetyl-1-14C]- Discontinued | MC 1482 |
| Uridine 5'-diphospho-N-acetyl-D-glucosamine, [glucosamine-14C(U)]- Discontinued | MC 1483 |
| Uridine 5'-diphospho-N-acetyl-D-glucosamine, [glucosamine-6-3H]- Discontinued | MT 1638 |
| Uridine 5'-diphospho-N-acetylglucosamine, [acetyl-3H]- Discontinued | MT 1547 |
| Uridine 5'-monophosphate, diammonium salt, [14C(U)]- | MC 1488 |
| Uridine 5'-monophosphate, diammonium salt, [2-14C]- | MC 180 |
| Uridine 5'-monophosphate, diammonium salt, [5-3H]- | MT 691 |
| Uridine 5'-monophosphate, diammonium salt, [5,6-3H]- | MT 1529 |
| Uridine 5'-triphosphate, tetraammonium salt, [2-14C]- | MC 450 |
| Uridine 5'-triphosphate, tetraammonium salt, [5-3H]- | MT 553 |
| Uridine 5'-triphosphate, tetraammonium salt, [5,6-3H]- | MT 925 |
| Ursodiol, [carboxyl-14C]- | MC 2552 |