Microscopy Quiz Review Flashcards
How will you adjust the diaphragm for a thin, translucent sample?
Reduce the light
How will you adjust the diaphragm for a thicker sample with dense structural components?
Increase the amount of light
How do you calculate the total magnification?
Magnification of eyepiece x magnification of objective
Practice: what is the total magnification for 15x eyepiece and 100x objective
1500x
Describe how to prepare cheek cells for imaging using the temporary mount technique and a stain
- swab the inside of your cheek
2.transfer the cheek swab into a drop of water on a clean slide - Use the stain Crystal-Violet Iodine Complex
We use CVI because it binds peptidoglycan (PG) which is the component in bacteria cells, good for bacteria
If you are looking at a sample under low power and its blurry, how can you focus it?
use the coarse focus knob to get the object into focus
What is the purpose of using a stain in microscopy?
- enhance visualization of the cell
-enhance cellular components under a microscope
What does methylene blue bind to?
Binds to DNA, good for the nucleus
How would methylene blue bind to a prokaryotic cell?
Everything would appear to be a dark blue color because it doesn’t have membrane bound organelles
How would methylene blue bind to a prokaryotic cell?
The nucleus would appear a dark blue color
What does iodine bind to? What would you expect it to bind in?
Iodine binds starch
you would see iodine bind in a banana
What organisms would you stain with a gram stain?
Bacteria
What is in a gram stain? (two components)
Crystal Violet and Iodine
What does gram stain bind to?
Peptidoglycan, coloring cells purple
Gram Positive Bacteria
These are bacteria that have thick peptidoglycan which is a layer of stain crystal-violet iodine is attracted to.
Gram Negative Bacteria
These are bacteria that do not have a thick layer of peptidoglycan
-crystal violet iodine complex is unable to be trapped within the structure
-the bacteria can hold the safranin having a red appearance under the microscope
What are the three shapes of bacteria?
coccus, bacillus, spirillum