Corynebacterium diphtheriae can be grown within 6-8 hour on

The usual media employed for the cultivation of diphtheria bacilli are Loeffler's serum slope and Tellurite blood agar. Loeffler's serum slope: Diphtheria bacilli grow on Loeffler's serum slope very rapidly and colonies can be seen in 6-8 hours, long before other bacteria grow. Colonies are first small, circular white opaque discs but enlarge on continued incubation and may acquire a distinctly yellow tint. Reference: Textbook of Microbiology; Anathanarayan and panicker's; 10th edition; Page no: 242