Lecture 1 Microscopy

Question 1

What is histology?

Answer 1

Study of tissue, structure of tissues

Question 2

True or False: Magnification does equal resolution

Answer 2

False, it does not

Question 3

Who help propelled microscopes?

Answer 3

Carl zeiss

Question 4

______ is used for observation of intact specimens at relatively low magnification.

Answer 4

Stereomicroscope

Question 5

______ is used for histological sections and cells

Answer 5

Compound light microscope Upright and Inverted.

Question 6

______ is used to view subcellular details

Answer 6

Electron microscope Transmission and scanning.

Question 7

A _______ is an optical instrument having a magnifying lens or a combination of lenses for inspecting objects too small

Answer 7

microscope

Question 8

What is the visible spectrum range?

Answer 8

400-700nm

Question 9

What are the 3 basic dimensions of light?

Answer 9

Intensity, frequency, polarization

Question 10

______ (amplitude) which is related to the perception of ______

Answer 10

Intensity, brightness

Question 11

______ (wavelength), perceived as ______

Answer 11

Frequency. colour

Question 12

______ (angle of vibration) which is not or weakly perceptible to humans

Answer 12

Polarization

Question 13

______ is the minimal distance of two points that can be distinguished.

Answer 13

Resolution (airy discs)

Question 14

______ is an estimate of how much light from the sample is collected by the objective

Answer 14

numerical aperture

Question 15

True or False: More light = higher resolution

Answer 15

True

Question 16

What is the equation for numerical aperture?

Answer 16

NA = n sin α n = refractive index α = angle of incident illumination

Question 17

True or False: Numerical aperture determines resolution

Answer 17

True

Question 18

______ is defined by magnification by the objective x the magnification by eyepiece

Answer 18

Magnification

Question 19

True or False: maximum magnification does not mean maximum resolution!

Answer 19

True

Question 20

What is wrong with this image?

Answer 20

Condenser not properly focused -uneven illumination

Question 21

What are the 6 types of contrasting techniques?

Answer 21

Brightfield

Darkfield

Phase Contrast

Polarization Contrast

Differential Interference Contrast (DIC)

Fluorescence

Question 22

What is brightfield microscopy used for?

Answer 22

specimens that can be contrasted via dyes.

Question 23

True or False: Only light that is scattered by structures in the sample enters the objective

Answer 23

True

Question 24

What is darkfield microscopy used for?

Answer 24

People use it a lot to look at Diatoms and other unstained/ colourless specimens

Question 25

True or False: Phase contrast is invasive

Answer 25

False, not invasive, cells can be alive

Question 26

What is polarization contrast used for?

Answer 26

used to look at materials with birefringent properties (ie, collagen)

Question 27

______ makes better use of the numerical aperture of the system and allows the microscope to achieve excellent resolution.

Answer 27

DIC

Question 28

How do you prepare a tissue sample?

Answer 28

Formalin fixation, paraffin embedding (fixation, dehydration w/ alcohol to 100%, clearing -xylene, infiltration - melted paraffin - embedding- placed in small mold to harden)

Question 29

______ is used in medical conditions because of faster turnover time

Answer 29

Cryosectioning

Question 30

______ samples are critically pointed dried and coated with a conductive material (gold).

Answer 30

SEM

Question 31

______ is stained with heavy metals and the area is very small

Answer 31

TEM