Lab IA: Introduction to Microscopy

Question 1

Name all 3 important considerations

Answer 1

• degree of magnification
• degree of resolution
• 3D or 2D

Question 2

Name 2 branches of microscopy

Answer 2

Light Microscopy and Electron Microscopy

Question 3

Name one big advantage of Light Microscopy

Answer 3

It can be used to view live specimens

Question 4

Name one big advantage of Electron Microscopy

Answer 4

Much higher magnification and resolution power

Question 5

Name one big DISadvantage of Electron Microscopy

Answer 5

Specimen is killed during the procedure

Question 6

Name one big DISadvantage of Light Microscopy

Answer 6

Lower Magnification & resolution power

Question 7

Name a microscope that provides a 3-dimensional view of a specimen that the compound light microscope does not

Answer 7

the stereoscopic microscope

Question 8

What is commonly used when viewing a specimen under a compound light microscope such as cells?

Answer 8

Stains

Question 9

What do stains do?

Answer 9

highlight structures compared to the background by ENHANCING STRUCTURES

Question 10

Questions on components of the light microscope…

What supplies the initial magnified image of the specimen?

Answer 10

The Objective Lenses

Question 11

Allows the user to change objective lenses without
damaging them

Answer 11

The revolving nosepiece

Question 12

Further magnifies the image (10X) from the objective

Answer 12

Oculars (Eyepieces)

Question 13

Provides illumination of the specimen

Answer 13

Light Source, Light Intensity Knob, and
On/Off switch

Question 14

Supports the entire microscope.

Answer 14

Base

Question 15

Supports the body tube and lenses. (you use it to carry)

Answer 15

Arm

Question 16

The function of Iris Diaphragm & Lever

Answer 16

Controls the amount of light entering and leaving the
condenser.

Question 17

Collects and concentrates light onto the specimen and
projects image onto the front lens of the objective in place

Answer 17

Condenser

Question 18

Clips a slide into place and allows user to move slide
in the x plane (left to right)

Answer 18

Mechanical Stage (Slide Holder)

Question 19

It provides a platform for the specimen and allows the user to move the specimen in the y plane

Answer 19

Sample stage

Question 20

What manoeuvers the sample stage & mechanical stage

Answer 20

The stage control knob

Question 21

Adjusts the height of the sample stage relative to the
objective to focus the specimen.

Answer 21

Coarse and Fine Focus Adjustment Knobs
Coarse (big) & Fine (small)

Question 22

Condenser Adjustment Lever

Answer 22

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))

Question 23

What is the name of the microscope used in this lab?

Answer 23

The Compound Light Microscope

Question 24

3 micrometers in millimeters and nanometers

Answer 24

0.003 millimiters
3000 nanometers

Question 25

How does the orientation of the image compare to the actual orientation of the specimen on the sample stage?

Answer 25

The orientation is INVERSED

Question 26

When the slide is moved to the RIGHT, the image in the field of view moves to which side?

Answer 26

LEFT

Question 27

When the slide is moved AWAY FROM YOU, the image in the field of view moves...

Answer 27

TOWARDS YOU

Question 28

Why don't we use the COARSE focusing knob with 10X, 40X or 100X? (3)

Answer 28

- specimen slide may break - objective lens may be damaged - the working distance is TOO SMALL and the objective lens may hit the slide

Question 29

In what position should the condenser be when viewing a specimen with the 10X and 40X objective?

Answer 29

10X: condenser down, lever up 40X: condenser up, lever down

Question 30

What is the Ocular Magnification?

Answer 30

10X

Question 31

What is the TOTAL magnification, is the objective magnification is 4X?

Answer 31

4 x 10 = 40X

Question 32

What is the TOTAL magnification, is the objective magnification is 40X

Answer 32

40 x 10 = 400X

Question 33

Are magnification and working distance directly or inversely proportional? (explain)

Answer 33

INVERSELY Big magnification = little working distance Low magnification = Big working distance

Question 34

What is also inversely proportional to magnification?

Answer 34

the depth of field (focal plane)

Question 35

What is the formula to calculate the field diameters?

Answer 35

tot mag1 x field dia1 = tot mag2 x field dia.2

Question 36

If total magnification is 40X what is the field diameter in mm and um?

Answer 36

40X = 4 mm = 4000 um

Question 37

If total magnification is 100X what is the field diameter in mm and um?

Answer 37

100X = 1.6 mm = 1600um

Question 38

If the field diameter is 4.5mm what should be the magnification and what is the field diameter in um?

Answer 38

4.5mm = 4500 um 4X objective

Question 39

If the field diameter is 1.8mm what should be the magnification and what is the field diameter in um?

Answer 39

1.8 mm = 1800um 10X objective

Question 40

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

Answer 40

TRUEEE

Question 41

TRUE OR FALSE: The sample stage should be brought all the way down before storage.

Answer 41

TRUE

Question 42

TRUE OR FALSE: Microscopes should be put away with the 40X objective in place.

Answer 42

FALSE: 4X

Question 43

TRUE OR FALSE: Microscopes should be placed in the cabinet with the objective lenses facing out.

Answer 43

FALSE: the back