Lab IA: Introduction to Microscopy Flashcards
Name all 3 important considerations
- degree of magnification
- degree of resolution
- 3D or 2D
Name 2 branches of microscopy
Light Microscopy and Electron Microscopy
Name one big advantage of Light Microscopy
It can be used to view live specimens
Name one big advantage of Electron Microscopy
Much higher magnification and resolution power
Name one big DISadvantage of Electron Microscopy
Specimen is killed during the procedure
Name one big DISadvantage of Light Microscopy
Lower Magnification & resolution power
Name a microscope that provides a 3-dimensional view of a specimen that the compound light microscope does not
the stereoscopic microscope
What is commonly used when viewing a specimen under a compound light microscope such as cells?
Stains
What do stains do?
highlight structures compared to the background by ENHANCING STRUCTURES
Questions on components of the light microscope…
What supplies the initial magnified image of the specimen?
The Objective Lenses
Allows the user to change objective lenses without
damaging them
The revolving nosepiece
Further magnifies the image (10X) from the objective
Oculars (Eyepieces)
Provides illumination of the specimen
Light Source, Light Intensity Knob, and
On/Off switch
Supports the entire microscope.
Base
Supports the body tube and lenses. (you use it to carry)
Arm
The function of Iris Diaphragm & Lever
Controls the amount of light entering and leaving the
condenser.
Collects and concentrates light onto the specimen and
projects image onto the front lens of the objective in place
Condenser
Clips a slide into place and allows user to move slide
in the x plane (left to right)
Mechanical Stage (Slide Holder)
It provides a platform for the specimen and allows the user to move the specimen in the y plane
Sample stage
What manoeuvers the sample stage & mechanical stage
The stage control knob
Adjusts the height of the sample stage relative to the
objective to focus the specimen.
Coarse and Fine Focus Adjustment Knobs
Coarse (big) & Fine (small)
Condenser Adjustment Lever
Controls the distance of the condenser to the sample
stage
Lever down = Condenser up;
Lever up = Condenser down.
(the lower the magnification, the higher the condenser
should be (i.e. the lever should be down))
What is the name of the microscope used in this lab?
The Compound Light Microscope
3 micrometers in millimeters and nanometers
0.003 millimiters
3000 nanometers
How does the orientation of the image compare to the actual orientation of the specimen on the sample stage?
The orientation is INVERSED
When the slide is moved to the RIGHT, the image in the field of view moves to which side?
LEFT
When the slide is moved AWAY FROM YOU, the image in the field of view moves…
TOWARDS YOU
Why don’t we use the COARSE focusing knob with 10X, 40X or 100X? (3)
- specimen slide may break
- objective lens may be damaged
- the working distance is TOO SMALL and the objective lens may hit the slide
In what position should the condenser be when viewing a specimen with the 10X and 40X
objective?
10X: condenser down, lever up
40X: condenser up, lever down
What is the Ocular Magnification?
10X
What is the TOTAL magnification, is the objective magnification is 4X?
4 x 10 = 40X
What is the TOTAL magnification, is the objective magnification is 40X
40 x 10 = 400X
Are magnification and working distance directly or inversely proportional? (explain)
INVERSELY
Big magnification = little working distance
Low magnification = Big working distance
What is also inversely proportional to magnification?
the depth of field (focal plane)
What is the formula to calculate the field diameters?
tot mag1 x field dia1 = tot mag2 x field dia.2
If total magnification is 40X what is the field diameter in mm and um?
40X = 4 mm = 4000 um
If total magnification is 100X what is the field diameter in mm and um?
100X = 1.6 mm = 1600um
If the field diameter is 4.5mm what should be the magnification and what is the field diameter in um?
4.5mm = 4500 um
4X objective
If the field diameter is 1.8mm what should be the magnification and what is the field diameter in um?
1.8 mm = 1800um
10X objective
TRUE OR FALSE: the 3D viewing of a specimen is best done at the highest magnification, b/c the depth of field allows you to move through the thinnest slide of the specimen
TRUEEE
TRUE OR FALSE: The sample stage should be brought all the way down before storage.
TRUE
TRUE OR FALSE: Microscopes should be put away with the 40X objective in place.
FALSE: 4X
TRUE OR FALSE: Microscopes should be placed in the cabinet with the objective lenses facing out.
FALSE: the back
