microbiology 4 Flashcards
tiny ruler within the eyepiece of a microscope that measures sizes of microbes
OCULAR MICROMETER
optical instrument that is used to observe tiny objects, often subjects that cannot be seen by our naked eyes.
MICROSCOPE
Types of Microscope:
SIMPLE MICROSCOPE
COMPOUND MICROSCOPE
defined as a microscope containing only one
magnifying lens.
SIMPLE MICROSCOPE
microscope that contains more than one magnifying lens
COMPOUND MICROSCOPE
these are photos taken through the lens system of compound microscopes
PHOTOMICROGRAPHS
contains two magnifying lens systems. Uses light as source of illumination
COMPOUND LIGHT MICROSCOPE
unstained organisms are observed against dark background
DARKFIELD MICROSCOPE
used to observe morphology of microorganisms
BRIGHTFIELD MICROSCOPE
can be used to observe unstained living
microorganisms
PHASE-CONTRAST MICROSCOPE
- fluorescent dye attached to organisms
– primarily an immunodiagnostic technique
– used to detect microbes in cells, tissues and clinical specimens
– contain a built-in ultraviolet light source when it strikes certain dye and pigment, it
glows against dark background
FLOURESCENCE MICROSCOPE
Two types of Electron Microscope:
TRANSMISSION ELECTRON MICROSCOPE(TEMs)
SCANNING ELECTRON MICROGRAPHS(SEMs)
uses an electron beam as source of illumination and magnets to focus the beam
ELECTRON MICROSCOPE
magnify further the image formed
OCULAR LENS/EYEPIECE
Components of the Compound Light Microscope
OCULAR LENS/EYEPIECE
Revolving nosepiece
OBJECTIVE LENSES
STAGE
IRIS DIAPHRAGM CONTROL ARM
CONDENSER
COLLECTOR LENS WITH FIELD
DIAPHRAGM
RHEOSTAT CONTROL KNOB
FIELD DIAPHRAGM LEVER
ON/OFF SWITCH
BASE
CONDENSER CONTROL KNOB
FINE and COARSE ADJUSTMENT KNOB
BINOCULAR BOD
ARM
enables scientists to observe living cells at extremely high magnification
ATOMIC FORCE MICROSCOPE
– specimen is viewed on screen
– has a tall column at the top of which an electron gun fires a beam of electrons downward
– has excellent resolution that allows examination of cellular and viral ultrastructure
– specimen is not living and reveals internal features of thin specimens
TRANSMISSION ELECTRON MICROSCOPE(TEMs)
holds objectivce lenses
Revolving nosepiece
– specimen is viewed on screen
– has a shorter column and instead of being placed into the electron beam, the
specimen is placed at the bottom of the column
– gives illusion of depth (2D) which is useful for examining surface features of cells and virus
– specimen is nonliving and resolution is less that of TEM
SCANNING ELECTRON MICROGRAPHS(SEMs)
used to magnify objects placed on the stag
OBJECTIVE LENSES
flat surface on which the specimen is placed
STAGE
used to adjust the amount of light passing through the condenser
IRIS DIAPHRAGM CONTROL ARM
contains a lens system that focuses light onto the specimen
CONDENSER
controls the amount of light entering the condenser
COLLECTOR LENS WITH FIELD DIAPHRAGM
used to adjust the amount of light passing through the collector lens
FIELD DIAPHRAGM LEVER
controls the amount of light emitted from the light source
RHEOSTAT CONTROL KNOB
turns the light source on and off
ON/OFF SWITCH
contains the light source
BASE
used
to adjust the height of the condenser
CONDENSER CONTROL KNOB
used to focus the objective lenses
FINE and COARSE ADJUSTMENT KNOB
holds the ocular lenses in their proper locations
BINOCULAR BODY
supports the binocular body and the revolving nosepiece
ARM
low power objective
X 10
scanning objective
X4
high dry objective
X 40
oil immersion objective
X 100
