Virtual Microscope Lab
Introduction
What is Gram staining?
What safety equipment should you wear when doing this lab in an actual laboratory?
Parts of the Microscope
What type of lenses are rotated on the nosepiece?
If you are using only the lens in the eyepiece, how many times is the specimen magnified?
Which focus adjustment moves the stage up and down?
What adjusts the amount of light on the slide?
What holds the slide in place?
Set Up
There are three objectives on your microscope. List the number on each one.
Which objective will you be starting with?
If you are using the 10x objective, what is your total magnification?
Low Magnification
What type of organism will you be looking at through the microscope?
True or False? You always start with the brightest amount of light and then slowly decrease until your specimen becomes clear.
When focusing on a specimen, which adjustment knob do you always start with?
When viewing a specimen, start with the ______objective and place the stage as
______to the objective as possible.
Once you see a vague image using the coarse adjustment, why should you not use it again?
Draw what you see at 100x-
When you switch to higher magnification, how should your slide be positioned on the stage?
High Magnification
What are two of the characteristics of bacteria that we need more magnification to see?
If you are using the objective marked 40x,
what is your total power of magnification?
Draw what you see at this power of magnification-
Oil Immersion
What is the most powerful objective on the microscope?
What is the purpose of the oil on the slide?
What should you do before you use the oil lens?
How much oil should you put on the slide?
What type of oil are you using?
Which objective is the only one made to be used with oil?
Why should you only use the fine focus with the oil immersion lens?
Draw the bacteria at this power of magnification-
What characteristics do you see with the oil immersion lens that weren’t apparent at the lower powers?
Discussing Results
What color are gram positive bacteria?
What color are gram negative bacteria?
What does it mean if there are gram negative bacteria in the yogurt?
Name two bacteria that are gram negative.
Why might there be gram negative bacteria in the yogurt sample?
Clean Up
What is an autoclave?
In a microbiology lab, what is the usual temperature and time set on the autoclave?
Conclusion
As a result of your hard work, what did you learn about your yogurt sample?
What might happen if this yogurt is consumed? (This is not in the lab, you will have to Google it.)