disc sensitivity method

disc sen·si·tiv·i·ty meth·od

a procedure for testing the relative effectiveness of various antibiotics; small discs of paper (or other suitable material) are impregnated with known, appropriate amounts of antibiotic, and then placed on the surface of semisolid medium that has been previously inoculated with the organism being tested; after suitable periods of incubation at 37°C, the lack of growth in zones about the various discs indicates the relative effectiveness of the antibiotic.