28.  This is a gram stain of a culture that your instructor…

28.  This is a gram stain of a culture that your instructor gave you.  Describe what you are looking at.  Is this a pure or mixed culture?  If mixed what is the first thing you should do to begin to identify the organisms? What is the total magnification of the image on this slide?          

15.  Nitrate reduction test can be used to differentiate bet…

15.  Nitrate reduction test can be used to differentiate between Pseudomonads and the Enterobacteriaceae.  You innoculated your Nitrate broth with your unknown; after incubation you added 5 drops of reagent A and 5 drops of reagent B.  You observed a Red color within 2 minutes.  Is this a + or a – reaction?