Brightfield Microscopy

Question 1

A microscope that allows light rays to pass directly to the eye without being deflected by an intervening opaque plate in the condenser is called a

Answer 1

brightfield microscope

Question 2

All microscopes have a basic frame structure, which includes the

Answer 2

arm and base

Question 3

The horizontal platform that supports the microscope slide is called the

Answer 3

stage

Question 4

is used for holding and moving the slide around on the stage

Answer 4

stage adjustment

Question 5

vary the intensity of light

Answer 5

light intensity control

Question 6

Most microscopes have some provision for reducing light intensity with a

Answer 6

neutral density filter

Question 7

All compound microscopes have three lens systems:

Answer 7

oculars, the objectives, and the condenser

Question 8

is a complex piece, located at the top of the instrument, that consists of two or more internal lenses and usually has a magnification of 10x

Answer 8

ocular or eyepiece

Question 9

ocular or eyepiece is a complex piece, located at the top of the instrument, that consists of two or more internal lenses and usually has a magnification of ______

Answer 9

10x

Question 10

collects and directs the light from the lamp to the slide being studied

Answer 10

condenser

Question 11

regulates the amount of light that reaches the slide

Answer 11

diaphragm

Question 12

are used for bringing objects into focus when studying an object on a slide

Answer 12

coarse adjustment and fine adjustment knob

Question 13

in reality the limit for most light microscopes is 1000, which is set by an intrinsic property of lenses called

Answer 13

resolving power

Question 14

its ability to completely separate two objects in a microscopic field.

Answer 14

resolving power

Question 15

is a mathematical expression that describes how the condenser lens concentrates and focuses the light rays
from the light source

Answer 15

Numerical aperture

Question 16

should be placed over the light source because the shorter wavelength of the resulting light will provide maximum resolution

Answer 16

blue filter

Question 17

is defined as the range of distance in front of and behind a focused image within which other objects will appear clear and sharply defined

Answer 17

Depth of field

Question 18

When carrying your microscope from one
part of the room to another, use _____________ to hold the
instrument

Answer 18

both hands

Question 19

In most laboratories _______________ are
used to protect the instruments during storage

Answer 19

dustcovers

Question 20

is often needed to reduce the intensity of light
below the lower limit allowed by the voltage control

Answer 20

neutral density filter

Question 21

On microscopes such as the ____________________, one can
simply place a neutral density filter over the light
source in the base.

Answer 21

Olympus CX41

Question 22

Three or more ________________ are usually present.
Note that they are attached to a _______________________,
which makes it possible to move them into position
over a slide.

Answer 22

objectives; rotatable nosepiece

Question 23

Objectives on most laboratory microscopes have magnifications of 10x, 40x, and 100x, designated as _______________________________________________, respectively

Answer 23

low-power, high-dry, and oil immersion

Question 24

To make diopter adjustments, one focuses first with
the _______________ only.

Answer 24

right eye

Question 25

Without touching the focusing knobs, diopter adjustments are then made on the left eye by turning the knurled ___________________________ on the left ocular until a sharp image is seen.

Answer 25

diopter adjustment ring

Question 26

For any light microscope, the limit of resolution
is about

Answer 26

0.2 μm.

Question 27

should be kept at the highest position that allows the maximum amount of light to enter the objective lens and therefore limit the amount of light lost due to refraction.

Answer 27

condenser

Question 28

should be used between the slide and the 100 objective lens. This is a special oil that has the same refractive index as glass. When placed between the specimen and objective lens, the oil forms a continuous lens system that limits
the loss of light due to refraction.

Answer 28

Immersion oil

Question 29

should be used to clean lenses

Answer 29

Only lint-free, optically safe tissues

Question 30

is a powerful solvent that could
possibly dissolve the lens mounting cement in some
objective lenses if it were used too liberally

Answer 30

Acetone

Question 31

Various liquids can be used for cleaning
microscope lenses like

Answer 31

Green soap with warm water, Xylene, Alcohol
and acetone

Question 32

The best way to determine if your eyepiece is
clean is to rotate it between the ______________________________ as
you look through the microscope

Answer 32

thumb and forefinger

Question 33

Good quality modern microscopes are usually
both ___________________ and ________________

Answer 33

parfocal; parcentral