<prompt> Which of the following is the most useful to differentiate micrococci from Staphylococci-Catalase testHugh Leifson testOxidase testAll of the above  <response>: Ans. is b i.e., Hugh Leifson test . The common laboratory test to differentiate between micrococci and Staphylococci is Hugh and Leifsons oxidation fermentation test in which micrococci show oxidative and Staphylococci show fermentative patterns. 