Antibiotic sensitivity disc are used to determine the effectivness of an antibiotic against a microorganism as a guide to antibiotic therapy.

The disc consist of a specific concentration of an antibiotic in mcg which is tested against a microorganism of a standard density, swabbed uniformly on an appropriate media following overnight incubation.

The antibiotic is impregnated on a filter paper disc in specified concentration. Both sides of the disc are printed with name and concentration for easy identification.