Test 2 - Microscopy

Question 1

What is the function of the base of the microscope?

Answer 1

Contains the transformer (resp for voltage/energy output entering the lamp), the rheostat (controls light intensity), the illuminator (lamp).

Question 2

What is the function of the mechanical stage?

Answer 2

• Support the specimen slides
• vernier scale = coordinates

Question 3

What is the function of the slide holder?

Answer 3

• Hold the specimen slides on the stage and allows for smooth movements with the co-axial adjustment knobs.

Question 4

What is the function of the stage adjustment knobs?

Answer 4

Move the slide in two direction to scan all parts of the slide.

Question 5

What is the function of the field diaphragm?

Answer 5

Controls area of illumination

Question 6

What is the function of the condenser?

Answer 6

Focus the light on the specimen

Question 7

What is the function of the condenser adjustment knobs?

Answer 7

Moves the condenser up and down to focus the light directly on the specimen.

Question 8

What is the function of the condenser centering screws?

Answer 8

Centers the condenser over the light.

Question 9

What is the function of the iris diaphragm?

Answer 9

Adjusts the NA of the condenser to equal that of the objective in use. improves contrast.

Question 10

What is the function of the objective lenses?

Answer 10

Responsible for primary magnification.

Question 11

What is the function of the rotating nosepiece?

Answer 11

Holds and rotates objective lenses.

Question 12

What is the function of the ocular lens?

Answer 12

• magnifies the image on the slide and must be adjusted to inter pupillary distance

Question 13

What is the function of the diopter rings?

Answer 13

Used to focus the eyepiece for the left eye.

Question 14

what is the function of the coarse and fine adjustment knobs?

Answer 14

Allows to move the stage up and down to focus the specimen under the objectives. Coarse = big adjustments fine= small fine adjustments.

Question 15

What is resolution?

Answer 15

When two objects that are close together can be distinguished apart. More detail = better resolution.

Question 16

What is magnification and what is total magnification?

Answer 16

ocular lens x Objective lens = TT magnification

Question 17

What is the numerical aperture?

Answer 17

It’s the ability of the microscope to render the finest detail distinctly visible.

Question 18

What is an empty magnification?

Answer 18

When the magnification has exceeded the resolving power and two distinct objects can no longer be distinguished. (Dumbbell)

Question 19

What is definition?

Answer 19

The capacity of the objective lens to render the outline of an object as distinct.

Question 20

What is spherical aberration?

Answer 20

is when many focal points produce a blurry image

Question 21

What is the objective lens system?

Answer 21

-Responsible for primary magnification
-The ability to separate detail depends on the capacity of the lens for gathering light

Question 22

What is coverslip glass?

Answer 22

Coverslips are little thin pieces of glass that adhere on top of a slide
purpose is to protect objective lenses and create even thickness.

Question 23

What is slide glass?

Answer 23

It’s colourless, plain glass slides with a thickness between 0.9 to 1.1 mm thick

Question 24

What is a plan-neofluar lens?

Answer 24

Contains fluorite which makes it idea for polarization microscopy due to its ability to transmit UV very well.

Question 25

What is a planapochromat lens?

Answer 25

A highly colour-corrected objective that allows for a greater NA.

Question 26

What are microscope ergonomics?

Answer 26

Workstations and chairs should be adjustable to allow user to sit comfortable at a microscope without causing strain to their necks, back, eyes by having to slouch down or look up at the microscope.

Question 27

What is Koehler illumination?

Answer 27

A process that provides optimum contrast and resolution by focusing and centering the light path and spreading it evenly over the field of view

Question 28

How should a microscope be cleaned?

Answer 28

Oculars
iris diaphragm
condenser
objective lense (low to high power)

Wipe down immediately after wards.

Lens paper and lens cleaner should be the only things used for cleaning microscope glass.

body of the microscope can be wiped down with gauze and dried afterwards.

Question 29

How should a microscope be stored?

Answer 29

It should be stored with a dust cover or in a dust free cupboard.

Should be carried with two hands and hitting it against anything should be avoided.

Question 30

What is a phase contrast microscope?

Answer 30

Allows to view specimens without staining. Has a annular ring which when perfectly lined up with the condenser annular will create light and shadow areas exposing the specimen.

Question 31

what is a polarizing microscope?

Answer 31

A bright-field microscope modified with polarizing filters which only allow for birefringent objects to be seen against the dark back ground.

Question 32

What is a darkfield microscope?

Answer 32

Utilizes the substage condenser to reflect light off of the object indirectly.
the field of view is dark because theres no light passing from the condenser to the objective.

Question 33

What is a fluorescent microscope?

Answer 33

Is a dark-field microscope with the ability to select for wavelength of light. Objects tend to fluoresce if they can absorb light, or they can be stained to.

Question 34

What is an electron microscope?

Answer 34

• transmission electron microscope TEM
  produces a 2D image of the object
  -Final image is projected onto a fluorescence screen or photographic plate.
  -scanning electron microscope SEM = 3D

Question 35

What is an inverted microscope?

Answer 35

microscope with its light source and condenser located above the stage pointing down

used in blood bank to view agglutination of RBC

Question 36

How should you troubleshoot a microscoope?

Answer 36

• Definition, light problem set koehler again.
• double image wrong eye distance.
• hazy, no definition of specimen - clean lenses
• Image shifting: check slide clips and stage screws
• cant focus oil, cover slip too thick or upside down slide.