Microscopic Techniques

Question 1

What shape are bacilli?

Answer 1

rod

Question 2

What shape is spirochetes?

Answer 2

spiral/ corkscrew

Question 3

What shape is the coccus?

Answer 3

sphere

Question 4

When did the microscope originiate?

Answer 4

17th century

Question 5

How does magnifying objects work?

Answer 5

combining convex and concave glass lenses

Question 6

who invented the telescope?

Answer 6

johannes kepler

Question 7

what is the book diotrice about

Answer 7

basic principles of light refraction and magnification

Question 8

who designed the first microscope?

Answer 8

gelileo

Question 9

who coined the term microscope

Answer 9

giovanni faber

Question 10

what did Robert Hooke do?

Answer 10

coined the word cell
invented compound microscope
wrote book micrographia

Question 11

what did antonie van leeuwenhoek do?

Answer 11

perfected the creation of simple lenses and built microscopes capable of 200x
observed bacteria, protozoans, sperm, and organelles

Question 12

what is aberration

Answer 12

distortion of an image from the ideal optical image

Question 13

what is the most common aberation?

Answer 13

spherical aberation

Question 14

how does spherical aberation occur?

Answer 14

light rays travel through thicker parts of the lense and are refracted to a different degree than those that travel through thinner parts

Question 15

who solved the problem of spherical aberation?

Answer 15

Joseph lister

Question 16

how did Joseph lister solve the problem of spherical aberation

Answer 16

placing lense at precise distances from each other

Question 17

what is chromatic aberation?

Answer 17

failure of a lens to focus all colors to the same convergence point

Question 18

how is chromatic aberration corrected?

Answer 18

Charles hall used a second lense of a different shape and refracting properties to realign colors with minimal impact on the magnification

Question 19

what is kohler illumination

Answer 19

uses Condensor and diaphragm to focus light rays onto specimen
**essential to modern light microscopy

Question 20

how does Kohler illumination improve the viewing of specimens

Answer 20

illumination and resolution are increased

Question 21

who discovered the importance of light diffraction

Answer 21

Abbe

Question 22

what do cones do?

Answer 22

they detect color

Question 23

where are cones located?

Answer 23

fovea

Question 24

what is magnification

Answer 24

the increase in the apparent size of the specimen being observed

Question 25

what is resolve

Answer 25

ability to clearly separate two objects that are very close together

Question 26

what is resolving power?

Answer 26

minimum distance existing between two objects when these objects can still be observed as separate entities

Question 27

what is brightfield microscopy

Answer 27

specimens are visualized because cells differentially absorb or scatter light resulting in the differences in contrast between the objects and their surroundings

Question 28

how many objective lenses does a compound microscope have?

Answer 28

at least three (10, 40, 100)

Question 29

what is the ocular lens and the magnification

Answer 29

IT is the lense you look through and is 10x

Question 30

what is the smallest object resolvable?

Answer 30

0.5 gamma per numerical aperture

Question 31

how can specimens be viewed on bright field microscopy

Answer 31

via wet mounts, fixed and stained on glass slides to permit better examination of morphology and internal structure

Question 32

what are dyes and their purpose

Answer 32

staining that can be used to improve the visibility

Question 33

what is simple stain

Answer 33

utilizes one dye to improve the contrast against the unstained background

Question 34

what are some examples of simple stain

Answer 34

methylene blue, rose bengal

Question 35

what are differential stains?

Answer 35

use two different stains designated as the primary dye and the counterstain

Question 36

what is an example fo differential stain

Answer 36

gram staining

Question 37

what are special strains?

Answer 37

used to identify specific cell components such as bacterial capsules and spores

Question 38

what is dark field microscopy

Answer 38

involve light scattering where light reaches the specimen from **only the slides**

Question 39

what is dark field microscopy good for?

Answer 39

observing microbial swimming motility

Question 40

what is phase contrast microscopy

Answer 40

uses a special condenser and a phase plate in the objective lens to **amplify the variation in phase and produce the higher contrast image**

Question 41

what does phase contrast microscopy do?

Answer 41

amplify the variation in phase and produce higher contrast images it also has better resolution than in brightfield

Question 42

What is DIC microscopy

Answer 42

polarizer makes two distinct beams that pass through the specimen and enhances subtle differences in the cell structure

Question 43

What is fluorescence microscopy

Answer 43

use fluorescence to reveal cells and their parts. specimen absorbs light at one wavelength and then emits light at a longer wavelength

Question 44

Why do cells fluoresce

Answer 44

they naturally contain fluorescent substances or they have been stained

Question 45

Direct Epifluorescent filter technique benefits

Answer 45

-target organism that can be concentrated -remove growth inhibitors -transferred to a different growth medium without physical injury

Question 46

what is immunofluorescence microscopy used for

Answer 46

detecting specific proteins and uses a dye that has been **covalently** attached

Question 47

What is FISH?

Answer 47

Fluorescent in situ hybridization

Question 48

Confocal laser-scanning microscopy

Answer 48

allows to access several planes of focus in specimen

Question 49

What is super-resolution imaging

Answer 49

shows how an individual an fluorescent protein moves within a living cell

Question 50

What is an electron microscope

Answer 50

uses electromagnetic lense, electrons, and a fluorescent screen

Question 51

what is a transmission electron microscope

Answer 51

clearly magnify an image 100x, electrons pass through or scatter to varying degrees

Question 52

What is negative staining

Answer 52

background is stained

Question 53

What is positive staining

Answer 53

the actual specimen is stained

Question 54

What is scanning electron microscopy

Answer 54

the specimen is coated with a thin film of a heavy metal the electron beam then scans back and forth across