Review Sheet 1: Chapter 2 - Microscopy

Question 1

Light Path: Bright Field Microscopy

Answer 1

Light Source, Condenser, Specimen, Objective, Occular

Question 2

Bright Field: Light Source

Answer 2

Halogen bulb

Question 3

Bright Field: Condenser

Answer 3

Lens that focuses light on specimen

Question 4

Bright Field: Specimen

Answer 4

Light goes through

Question 5

Bright Field: Objective

Answer 5

Lens that collects light from specimen

Question 6

Bright Field: Ocular

Answer 6

Lens that focuses light for your eyes

Question 7

Working Distance

Answer 7

• Property of the objective- Distance from specimen to objective that is ‘in focus’

Question 8

Focal Length

Answer 8

Distance to create an image with parallel light

Question 9

Resolution

Answer 9

-Smallest distance between 2 points that you can tell that there are 2 distinct points- Depends on 1. Wavelength of light 2. NA

Question 10

Numerical Aperture

Answer 10

• A measurement of how much light the lens can capture- Enhanced by oil.

Question 11

Bright Field: Which color light gives better resolution, red or blue?

Answer 11

Blue. Shorter wavelength

Question 12

What does this mean on an objective:100/1.2

Answer 12

100 x magnification1.2 NA

Question 13

5 ways to improve bright field microscopy

Answer 13

1. Staining2. Dark Field3. Phase Contrast4. DIC (Nomarski)5. Fluorescence Microscopy

Question 14

Staining

Answer 14

Colors samples with dye

Question 15

Dark Field

Answer 15

Hollow cone of light that misses the objective unless the specimen is there. If the specimen is there, the light will bend when it hits it and then hit the objective

Question 16

Phase contrast

Answer 16

Light that goes through a specimin shifts its wave position, giving enhanced contrast to cell edges.

Question 17

DIC (Nomarski)

Answer 17

Uses polarized light, so you view only part of the specimen with different refractive indexes

Question 18

Fluorescence Microscopy

Answer 18

Allows you to see fluorophores.

Question 19

Annular Stop

Answer 19

Part of Phase-Contrast microscopy

Question 20

2 Light paths used in Phase Contrast

Answer 20

Deviated and Undeviated light

Question 21

What happens to light after specimen in phase microscopy?

Answer 21

Light diffracts 1/4 wavelength, allowing it to hit the objective

Question 22

Why would you use phase microscopy

Answer 22

Studying motility, shape of living cells, endospores, because their refractive index is different from water.

Question 23

What kind of light is seen by DIC?

Answer 23

Polarized

Question 24

Fluorophore

Answer 24

Molecule that absorbs excitation light and emits fluorescent light

Question 25

Fluorescent light path

Answer 25

Hg Arc lamp, Exciter filter, Dichroic, Specimen, Dichroic, Emission/Barrier filter

Question 26

Excitation Filter

Answer 26

Removes long wavelengths, allows excitation light through

Question 27

Dichroic

Answer 27

Reflects short wavelengths, allows long wavelengths through

Question 28

Emission (Barrier) filter

Answer 28

Blocks UV light and allows visible light through

Question 29

Wy use Hg Arc lamp?

Answer 29

It gives an intense beam of light needed for fluorescent microscopy

Question 30

Confocal Microscopy

Answer 30

Uses a pinhole to focus