<prompt> Earliest growth of diphtheria is detect on which media ?Potassium tellurite media with ironMcConkeys agarDorset egg mediumLoefflers serum slope  <response>: Ans. is d i.e., Loefflers serum slope Diphtheria bacilli grow on Loefflers serum slope very rapidly and colonies can be seen in 6-8 hours, long before other bacteria grow. 