Question

Question 1

What is the last step of successfully preparing a bacterial smear for a simple stain?

		Spread cells with inoculating loop
		Label the slides
		Heat fixation
		Air dry the smear

Question 2

When looking at your smear under the microscope, all you see is darkness (despite shining light through your slide)- the best explanation is:

		all your bacteria are dead
		your smear was too thin
		forgot to add the bacteria
		your smear was too thick

Question 3

If a microbe can ferment lactose and its fermentation products include lactic acid and CO2, then the results for this assay should be:

		the broth will appear yellow and there will be a gas bubble in the Durham tube
		the broth will appear red and there will be no gas bubble in the Durham tube
		the broth will appear yellow and there will be no gas bubble in the Durham tube
		the broth will appear red and there will be a gas bubble in the Durham tube

True/Flase

Question 1

If the result for this carbohydrate test is negative, then the organism had NO growth in the tube.

Question 2

The biochemical basis of the Gram stain is the thickness of peptidoglycan layers surrounding cells. Therefore a Gram positive cell with a thin layer of peptidoglycan should stain as Gram negative.

Question 3

If the iodine is not applied during the Gram stain, then gram positive cells will likely stain pink

Question 4

A simple stain allows you to see the cell shape and arrangement.

Question 5

If there were no limit to magnification, a light microscope could enlarge microbes infinitely.

Question 6

When doing a bacteria smear from a broth medium you should first place one to two loopfuls of water on the center of the slide?