phen·yl·thi·o·car·ba·mide 
(fĕn′əl-thī′ō-kärbə-mīd′, -kär-bămīd, fē′nəl-)
(fĕn′əl-thī′ō-kärbə-mīd′, -kär-bămīd, fē′nəl-)n. Abbr. PTC
A crystalline compound, C7H8N2S, that tastes intensely bitter to people with a specific dominant gene and is used to test for the presence of the gene. Also called phenylthiourea.