[A study on the decrease of potency of PPD solution. Experiments using  3 H-PPD].
D000818:Animals; D004355:Drug Stability; D006168:Guinea Pigs; D012996:Solutions; D013501:Surface-Active Agents / Q000494:pharmacology; D014373:Tuberculin / Q000592:standards*
D012996:Solutions; D013501:Surface-Active Agents; D014373:Tuberculin