Lab 1

Question 1

list the major branches of microscopy + describe advantages and disadvantages

Answer 1

• Light = can be used to view live specimens( :) ), 3D view (stereoscopic microscope )
• electron = kills live specimens ( :( ) , higher magnification + resolution ( :) )

Question 2

Identify the various components of a compound light microscope (with picture) (1-20)

Answer 2

-Arm
-Oculars/eyepieces
-Objective lenses
-Revolving nose piece
-Condenser
-Diaphragm lever
-Stage
-Mechanical stage
-Lighting on/off
-Brightness control knob
-Coarse focus knob
-Fine focus knob

Question 3

What does the arm do ?

Answer 3

Supports the body tube and lenses. Use the arm to
carry your microscope.

Question 4

What do the oculars do ?

Answer 4

Further magnifies the image (10X) from the
objective and puts it in a form and position suitable
for viewing. Can be adjusted to fit the users
interpupillary distance and correct for vision
differences (except astigmatism) in the users eyes.

Question 5

What do objective lenses do ?

Answer 5

Supplies the initial magnified image of the
specimen. The magnification of each objective is written on its side.

Question 6

What does the revolving nose piece do ?

Answer 6

Allows the user to change objective lenses without damaging them. The objectives should not be pushed or pulled to change lenses.

Question 7

What does the condenser do ?

Answer 7

Collects and concentrates light onto the specimen
and projects image onto front lens of the objective in
place. Can be controlled to optimize contrast and
resolution of the image viewed and reduce glare.
Controlled using the Condenser Adjustment Lever

Question 8

What does the diaphragm lever do ?

Answer 8

Opening and closing the aperture diaphragm
changes the amount of light as well as changes the
image contrast, resolution of the image

Question 9

What does the stage do ?

Answer 9

Holds the specimen and allows you to move the specimen forward and back and left and right to find the part you want to observe.

Question 10

what does the mechanical stage do ?

Answer 10

The slide glass specimen is held by the
movable claw. When holding the specimen,
make sure the cover glass is on top.

Question 11

What does the brightness control knob do ?

Answer 11

Turn to adjust to the desired brightness

Question 12

What do the coarse focus knobs do ?

Answer 12

Adjusts the height of the sample stage relative to
the objective to focus the specimen. The Coarse
Focus Knob is very sensitive (in terms of the
change in height as the knob is rotated) and allows
for the initial focusing (only used with the 4X
objective

Question 13

What does the fine focus knob do ?

Answer 13

The Fine Focus Knob is much less sensitive and allows for fine focusing when using any objective.

Question 14

how would you prepare a slide ?

Answer 14

-place specimen
-add water (paper e example )
-place plastic cover (coverglass)
-use toothpick or other tool to remove air bubbles

Question 15

How would you used CLM to magnify a specimen into a fine focus image ?

Answer 15

-put 4X objective
-turn on light
-raise condenser by pulling down on condenser control level
-look through oculars and adjust intensity of light
-adjust distance between oculars - circle of light = field of view