LAB 1 - MICROSCOPE Flashcards
lab 1
It uses glass lenses to bend and focus light rays and
create magnified images of small objects.
light microscope
It forms a dark image against a brighter background
BRIGHT FIELD MICRSOCOPE
lenses magnification starting from scanner to OIO
Scanner - 4x
LPO - 10x
HPO 40x
OIO 100 x
what is the refractive index of the cedar wood oil the glass has 1.5 refraction?
1.5
It decreases the amount of diffraction or bending
of light rays since it has the same refractive index
as glass, resolution must be at 100x
cedar wood oil
It enhances resolution and it is used to fill the space
between the objective lens and glass slide. Give the given example provided in the lab.
Cedar wood oil
It prevents light rays from dispersing and changing
wavelength after passing thru the samples
any mineral oil; lab based - cedar wood oil
a part of microscope where you Observes specimen, re-magnifies the image form by the
objective lens
Eye Piece Lenses (Ocular Lenses)
To compensate for observer’s eyesight in the left and
right eyes
Diopter Adjustment Ring
It determines the distance between the two eyes.
Interpupillary Distance Scale
A monocular or binocular tube which transmits the
image from the objective lens to ocular
Observation tube
It is used for holding the microscope
Arm
It holds the objectives
Rotating this part easily changes the magnification of
the objectives
Revolving nosepiece
Are the primary lenses that magnify the specimen
Objective lenses
Are the most important parts of the microscope which
must produce a clear image
Objective lenses
The higher the magnification number of an objective,
the greater the detail seen in specimen parts
Objective lenses
It focuses light through the specimen
Condenser
This incorporates a lens which collects illumination light
on the stage so that the objectives can perform at full
capability
Condenser
which objective magnification is used if the one you are observing is an adult form of parasite?
LPO or Scanner
It permits detailed examination of internal structures
in living organisms
phase contrast microscopy
It is used to identify medically important fungi grown
in culture.
PHASE CONTRAST MICROSCOPY
in phase contrast microscpe, The phase differences are seen through the
the microscope as different degrees of ___
brightness
do we need to stain specimen in phase contrast microscope?
no
2 types of light sources in phase contrast microscope
direct light and difracted light
It involves excitation of flourochrome by light
FLOURESCENT MICROSCOPY
Fluorescence microscope It uses which light and emit which light
it uses uv light and emit uv light
fluorescent microscope It use ___ to stain microorganisms
fluorochrome (dyes)g
give some example of fluorochrome (dyes)
acridine orange, auramine and
rhodamine, calcofluor white and fluorescein
isothiocynate (FITC)
what is the fluorochrome dye used in histology and bacte?
Acridine orange in histo and auramine rhodamine in bacte
It uses darkfield condenser that blocks light that
would enter the objective directly
DARK FIELD MICROSCOPY
It directs the light to hit the specimen at an oblique
angle, all other light that passes through the specimen
will miss the objective, thus making the background a
darkfield (organisms appear extremely bright against
a black field
DARK FIELD MICROSCOPY
dark field microscope is used to detect which parasite?
spirochetes (Treponema pallidum)
do we need o stain specimen in dark field microscope?
no
It uses electrons instead of light to visualize small objects. or as a source of light
electron microscope
It uses electromagnetic fields instead of lenses to form an
image on a fluorescent screen like a television screen
ELECTRON MICROSCOPY
what is the advantage of electron microscope
Advantages: objects smaller than 0.2um can be
visualized using this type of microscope with 100,000x
magnification: resolving power is greater
electron are useful for studying
for studying viruses fungi and microsporidian
parasites
resolution of electron microscope
Resolution: 0.5nm
fixative of electron microscope
Fixatives: glutaraldehyde or osmium tetroxide
dehydrating agents of electron microscope
alcohol or acetone
stains for electron microscope
lead citrate and uranyl acetate
2 types of elctron microscope
Transmission Electron Microscope (TEM) and Scanning Electron Microscope (SEM)
a type of electron microscope that needs Ultra-thin preparation of sample
and Allows to examine sample in different layers
Transmission Electron Microscope (TEM)
a type of electron microscope that only scans the surface of specimens
Scanning Electron Microscope (SEM)
is a measure of the relative velocity at
which light passes through a material.
Refractive Index
it refers to ability of the lenses to
separate closely distant objects.
Resolving Power
- it is necessary to make objects stand out from the
background. It is achieved by staining techniques
Contrast
for mula for total magnification
Total magnification
= Magnification of the
Objective Lens X Magnification of the Ocular Lens
fertilized or unfertilized
more rounded
fertilized
fertilized or unfertilized
thin shell
unfertilized
what does it mean if it’s corticaited
it has outer coating
what does it mean if it’s decorticated
no outer coating in the shell
a distinct characteristic of trichuris trichuria/trichiura
bipolar plugs
shape of trischuris trichuria/trichiura
stain used for trischuris
saline
stains used for ascaris lumbricoides
iodine
stain used for taenia
saline
