Microscopy

Question 1

Describe the part of a microscope:

Ocular lens

Answer 1

The ocular lens contributes to the magnification. Usually 10x. It is contained within the eyepiece of the microscope.

Question 2

Describe the part of a microscope:

Eye piece

Answer 2

Connects the ocular lens to the body tube.

Question 3

Describe the part of a microscope:

Body tube

Answer 3

The body tube is hollow space containing mirrors. Light is reflected through it to the eye pieces.

Question 4

Describe the part of a microscope:

Rotating nosepiece/ocular housing

Answer 4

The nosepiece is attached to the other end of the body tube. The nosepiece can rotate to allow the use of four different objective lenses.

Question 5

Describe the part of a microscope:

Scanning lens

Answer 5

The scanning lens is the one you start with.
It has a lowest power of 4x.

Question 6

Describe the part of a microscope:

Lower power lens

Answer 6

The low power lens has a power of 10x.

Question 7

Describe the part of a microscope:

High power lens

Answer 7

The high power lens has a power of 40x.

Question 8

Describe the part of a microscope:

Oil immersion lens

Answer 8

The oil immersion lens has a power of 100x.
Immersion oil must be used with this lens to prevent scattered light from causing a blurry image.

Question 9

Describe the part of a microscope:

Mechanical stage

Answer 9

The mechanical stage supports the specimen slide.

Question 10

Describe the part of a microscope:

stage clips

Answer 10

Holds the slide in place on the stage.
Also called slide holder.

Question 11

Describe the part of a microscope:

Mechanical stage control

Answer 11

two knobs hanging from the bottom of the stage for moving the stage left and right, closer, or farther away.

Question 12

Describe the part of a microscope:

Arm

Answer 12

The arm connects the body tube of the microscope to the base.

Question 13

Describe the part of a microscope:

Lamp

Answer 13

The lamp provides illumination and the intensity of light is controlled by the rheostat.

Question 14

Describe the part of a microscope:

Rheostat

Answer 14

The rheostat controls the amount of light emitted by the lamp.

Question 15

What is the purpose of the condenser?

Answer 15

adjusts the light to improve contrast of the image

Question 16

Describe the part of a microscope:

Condenser

Answer 16

The condenser bends the light to focus on to specimen.

Question 17

What are the markings on the iris diaphragm used for?

Answer 17

to keep the amount of light consistent for switching between lenses

Question 18

Describe the part of a microscope:

Iris diaphragm

Answer 18

an aperture to adjust the amount of light passing to the sample.

Question 19

Describe the part of a microscope:

Coarse focus

Answer 19

the outer ring of the focus raises and lowers the
stage in large increments.

Question 20

Describe the part of a microscope:

Fine focus

Answer 20

The fine focus knob raises and lowers the stage in small increments.

Question 21

When is the coarse focus used?

Answer 21

The coarse focus knob is only used with the scanning(4x) objective.

Question 22

Describe the part of a microscope:

Base

Answer 22

The base supports the microscope.

Question 23

With which objective lenses is oil used?

Answer 23

Only the 100x, the oil immersion lens!

Question 24

What is the range of viewing resolution via the microscope?

Answer 24

from 100 micrometers down to 1

Question 25

As a rule of thumb, light microscopes are used for what?

Answer 25

viewing cells,
studying bacteria,
tissue analysis.

Question 26

Name the factors that contribute to the quality of a microscope.

Answer 26

there are three
magnification
resolution
contrast

Question 27

Briefly define:
Magnification

Answer 27

refers to the increase in apparent size of the image.

Question 28

Briefly define:
Resolution

Answer 28

refers to the ability to distinguish fine detail.
(aka or resolving power)

Question 29

Briefly define:
Contrast

Answer 29

refers to the ability to distinguish objects such as cells, from the background.

Question 30

The goal of microscopy

Answer 30

is to create a magnified image of objects too small to be seen with the eye alone.

Question 31

Brightfield microscopes use a combination of what to view a specimen?

Answer 31

glass lenses and light

Question 32

Fields of study where a microscope is a necessary tool include

Answer 32

Cytology
Histology
Microbiology
Pathology

Question 33

Briefly define:
The field of view

Answer 33

is the amount of the slide you are able to see through the eyepiece.

Question 34

Briefly describe:
Total magnification

Answer 34

is the overall enlargement of the image of a specimen.

Question 35

Briefly describe oil immersion.

Answer 35

oil immersion is when a drop of immersion oil is added to the slide, contacting both the sample and objective. With this oil, less light is lost into air or scattered by the slide, increasing resolution.

Question 36

Briefly describe use of oil immersion as it relates to objective lenses.

Answer 36

Immersion oil can only be used with the 100X objective lens. The oil must be properly removed before using the 4X, 10X, or 40X objectives lenses.