Are you a "taster" or a "non-taster?" PTC paper is used to test whether or not a person can taste the bitter flavor of phenylthiocarbamide (PTC). The ability to taste or not taste PTC is conveyed by a single gene, TAS2R38, that codes for a taste receptor on the tongue. On average, 75% of people can taste PTC and 25% cannot. Each vial contains 100 testing strips. Order these testing strips online from agclassroomstore.com.