| Saccharin, [ring-14C(U)]- | MC 2419 |
| SAG, [3H]- (3-Chloro-benzo[b]thiophene-2-carboxylic acid (4-methylamino-cyclohexyl)-(3-pyridin-4-yl-benzyl)-amide, [3H]-) | MT 1908 |
| Salicylamide, [5-3H]- | MT 1757 |
| Salicylic acid, [7-14C]- | MC 1123 |
| Sangivamycin, [3H]- | MT 742 |
| Santocure TBSI, [phenyl-14C(U)]- | MC 2784 |
| Sapanisertib, [pyrazolo[3,4-d]pyrimidine-6-14C]- | MC 2775 |
| Saquinavir | M 1616 |
| Saquinavir, [benzylquinoline ring14C(U)]- | MC 2481 |
| Saquinavir, [3H]- | MT 1731 |
| Sarecycline, [3H]- | MT 2157 |
| SB-269970, [3H]- | MT 2177 |
| SB-674042, [3H]- | MT 2121 |
| SB-699551, [3H]- | MT 2095 |
| SBI-553, [3H]- | MT 2165 |
| SCH-527123 (Navarixin), [3H]- | MT 2124 |
| L-Serine, [14C(U)]- | MC 265 |
| L-Serine, [3H]- | MT 910 |
| L-Serine, [3-3H]- | MT 2041 |
| D-Serine, [3-3H]- | MT 944 |
| Z-D,L-Serine, [3-14C]- | MC 2344 |
| SHA-68, [3H]- | MT 2138 |
| Sinefungin, [8-3H]- | MT 985 |
| Sodium bicarbonate, [14C]- | MC208 |
| Sodium borohydride, [3H]- | MT 1848 |
| Sodium carbonate, [14C]- | MC 473 |
| Sodium cyanide, [14C]- | MC 256 |
| Sodium hyaluronate, [3H]- | MT 2074 |
| Sodium isobutyrate, [1-14C]- | MC 2022 |
| Sodium 4-methyl-2-oxopentanoate, [1-14C]- | MC 2409 |
| Sodium oleate, [1-14C]- | MC 406S |
| Sodium pyrithione, [2,6-14C]- | MC 2622 |
| Sodium risedronate, [ethyl-1-14C]- | MC 2495 |
| Sodium salicylate, [7-14C]- | MC 1123S |
| Solithromycin, [6-O-methyl-14C]- | MC 2758 |
| Sorafenib, [3H]- | MT 1907 |
| Sorafenib-N-Oxide, [3H]- | MT 1934 |
| Sorbitol, [14C(U)]- | MC 2587 |
| Sparfloxacin, [2-14C]- Discontinued | MC 1408 |
| Spectinomycin, [3H]- | MT 1758 |
| Spectinomycin sulfate, [bis-methylamino-14C]- | MC 2414 |
| Spironolactone, [dihydrofuran ring-3,4-14C]- | MC 2521 |
| SR8278, [3H]- | MT 2149 |
| ST-101, [3H]- | MT 2119 |
| Staurosporine, [3H]- | MT 1932 |
| Stearic acid, [1-14C]- | MC 172 |
| Stearic acid, [9,10-3H]- | MT 988 |
| Stearoyl Coenzyme A, [stearoyl-1-14C]- | MC 1439 |
| Stearoyl Coenzyme A, [stearoyl-9,10-3H]- | MT 1849 |
| Stearyl isethionate, sodium salt, [stearyl-1-14C]- | MC 2339 |
| Styrene, [vinyl-1-14C]- | MC 2659 |
| Succinic acid, [1,4-14C]- | MC 238 |
| Succinic acid, [2,3-14C]- | MC 268 |
| Succinic acid, [2,3-3H]- | MT 1528 |
| Succinic anhydride, [2,3-14C2]- | MC 2402 |
| N-Succinimidyl propionate, [1,2-14C]- | MC 2526 |
| N-Succinimidyl propionate, [propionate-2,3-3H]-....80-120 Ci/mmol | MT 919 |
| N-Succinimidyl propionate, [propionate-2,3-3H]-....40-80 Ci/mmol | MT 919M |
| Sucrose, [14C(U)]- | MC 266 |
| Sucrose, [3H]- | MT 1956 |
| Sulcotrione, [cyclohexanedione-2-14C]- | MC 2651 |
| Sulcotrione, [phenyl-14C(U)]- | MC 2452 |
| Sulfamethazine, [3,5-3H]- | MT 990 |
| 4,4'-Sulfonyldiphenol, [3H]- | MT 2012 |
| Sulfur, elemental, [35S]- Discontinued | MS 106 |
| Sulpiride, [3H]- | MT 2101 |
| Suramin sodium | M 823 |
| Suramin sodium, [3H]- | MT 823 |
| Sunitinib malate, [14C]- | MC 2704 |
| Synguanol monophosphate, diammonium salt | M 1944 |
| Syringol, [ring-13C(U)]- | MG 158 |