Microscopy Flashcards
is an instrument used to see
objects that are too small for the naked eye.
microscope
The science of investigating small objects using
such an instrument is called
microscopy.
means invisible to the eye unless
aided by a microscope.
Microscopic
1285
Glasses are invented
1590
Hans and zacharias janssen make a 9x magnifier
1609
Galileo Perfects the Microscope
1625
Giovannii Faber Coins the Word Microscope
The modern Microscope is Born
1800
1670
Antony Van Leeuwenhoek Perfects Microscope
1665
Robert Hooke Discovers Cells
1926
Richard Zsigmondy Wins Nobel Prize for the Ultra Microscope
1931
Max knoll and ernst Ruska Invent the Electron Microscope
1953
frits Zernike Wins Nobel for Phase Contrast Method
1986
Tunneling Microscope
magnification of up to 300 times
Stereo (Dissecting) Microscope
uses a laser light to scan samples that
have been dyed
Confocal Microscope
uses electrons rather than light for
image formation
Scanning Electron Microscope (SEM)
uses electrons in creating a magnified
image
Transmission Electron Microscope
(TEM)
Adjustments
and Support
Mechanical Parts
Enlarge the
specimen
Magnifying Parts
Provide the
light
Illuminating Parts
Bottommost portion that
supports the entire/lower
microscope
Base
Pillar
Part above the base that supports the
other parts
Allows for tilting of the
microscope for convenience of
the user
Inclination Joint
Curved/slanted part which is
held while carrying the
microscope
Arm/Neck
Attached to the arm and bears the lenses
Body Tube
Cylindrical structure on top of the body tube that
holds the ocular lenses
Draw Tube
Platform where object to
be examined is placed
Stage
Secures the specimen to the stage
Stage Clips
Allows the light to pass through the
specimen for the better view
Stage Opening (Aperture)
When turned, it raises or lowers the eyepiece in order
to adjust the focus for each eye. This improves the
magnification and also the clarity.
Diopter adjustment
Rotating disc where the objectives
are attached
Revolving/Rotating Nosepiece
This is also known as the body. It carries the optical parts in
the upper part of the microscope.
Head
Lies atop the nosepiece and keeps dust
from settling on the objectives
Dust Shield
Geared to the body
tube which elevates
or lowers when
rotated bringing the
object into
approximate focus
Coarse Adjustment
Knob
A smaller knob for delicate focusing
bringing the object into perfect focus
Fine Adjustment Knob
Elevates and lowers the
condenser to regulate the
intensity of light
Condenser Adjustment Knob
Lever in front of the condenser and which is
moved horizontally to open/close the diaphragm
Iris Diaphragm Lever
gather wavefronts from the
microscope light source and
concentrate them into a cone of light
that illuminates the specimen with
uniform intensity over the entire view
field
Condenser
Controls the amount of light reaching the specimen
* In most high quality microscopes include an Abbe
condenser with iris diaphragm.
Iris Diaphragm
Located beneath the stage and has
concave and plane surfaces to gather
and direct light in order to illuminate the
object
Mirror
A built-in illuminator beneath the stage
that may be used if sunlight is not
preferred or is not available
Electric Lamp
Another set of lens found on top of the body tube
which functions to further magnify the image
produced by the objective lenses. It usually
ranges from 5x to 15x.
Ocular / Eyepiece
Metal cylinders attached below
the nosepiece and contains
especially ground and polished
lenses
Objectives
Gives the lowest magnification,
usually 10x
LPO / Low Power Objective
Gives higher magnification usually 40x or 43x
HPO / High Power Objective
Gives the highest magnification, usually 97x or 100x, and is used wet
either with cedar wood oil or synthetic
OIO / Oil Immersion Objective
–provide observers with about
enough magnification for a
good overview of the slide
Scanning Objective (4x)
Ability of the lens to distinguish two objects that are
close together.
RESOLUTION
A function of objective lenses and its ability to
gather light.
NUMERICAL APERTURE
refractive index of the medium the lens is
working in
n
measurement of the cone light that enters
the objective.
sin θ
The most important feature of the optical system and influences the ability to distinguish between the fine details of a particular specimen
resolving power
200 nanometers
Compound Microscope
10 nanometers
Scanning Electron
Microscope
0.2 nanometers
Transmission Electron
Microscope
USEFUL MAGNIFICATION
(500x to 1,000x)
EMPTY MAGNIFICATION
(1,400x and beyond)
As magnification increases, detail
increases but
less of the cell is seen
Total Magnification
Magnification = Objective lens X Eyepiece lens
Refers to objectives
that can be changed
with minimal or no
refocusing.
PARFOCAL
Distance from the front lens
element of the objective to
the closest surface of the
coverslip when the
specimen is in sharp focus.
➢ Is determined by the linear
measurement of the
objective front lens to the
specimen surface
(objectives without
coverslips).
WORKING DISTANCE
Is the extent of the
observable area in
distance units.
➢ The area you see
under the microscope
for a articular
magnification.
➢ The diameter of the
circle that you see.
FIELD OF VIEW (FOV)
HOW TO CALCULATE
MICROSCOPE FIELD OF
VIEW (FOV)?
Field of view= field number (FN) divided by Magnification
Used to measure
minute distances or the
apparent diameters of
objects which subtend
minute angles
➢ 1 millimeter = 1,000
micrometers (1 x 103
)
➢ Given the example:
* 0.05mm X 1,000 μm
= 50 μm
MICROMETER
MEASURING WITH
MICROSCOPE
- Determine the diameter
of the field. - Estimate how many of the
object fit across the
diameter. - Divide the diameter by the number that fit
across to get the size of the object.
When is oil immersion objective used?
➢ used only at very large magnifications that require
high resolving power.
➢ use when you have a fixed (dead - not moving)
specimen that is no thicker than a few micrometers.
➢ Even then, use it only when the structures you wish to view are
quite small - one or two micrometers in dimension.
How does increased magnification affect the
field vision?
➢When magnification increases:
➢ the field of vision decreases.
➢ (by changing to a higher power lens), the working
distance decreases and you will see a much smaller slice of
the specimen.
➢ The lenses on your microscope, the length of the lens
increases and the lens aperture decreases in size.
