PRELIM: MICROSCOPE Flashcards
The simplest type of compound
microscope
BRIGHTSFIELD COMPOUND MICROSCOPE
refers to the fact that magnified objects appear as dark objects against a bright background.
Brightfield
means that a specimen positioned properly on the stage of a microscope and illuminated by a light source will
be magnified by a two-lens system.
Compound
THE PATH OF LIGHT
also known as the “light source”.
ILLUMINATOR
THE PATH OF LIGHT
Has lenses that direct the light rays through the specimen.
CONDENSER
THE PATH OF LIGHT
Light rays then pass into the objective lenses, the lenses closest to the specimen.
OBJECTIVE LENSES
THE PATH OF LIGHT
Then the image of the specimen is magnified again by the ocular lens or eyepiece.
OCULAR LENS
The oil used in oil immersion is???
CEDAR WOOD OIL
OIL IMMERSION OIL REFRACTIVE INDEX
1.516
The use of immersion oil improves the resolving power of the lenses.
If oil is not used with an oil immersion objective lens, the image becomes fuzzy, with poor resolution.
OIL IMMERSION OIL
STRUCTURAL COMPONENTS
Houses the optical parts in the upper part of the microscope.
HEAD/BODY
STRUCTURAL COMPONENTS
Connects to the base and supports the microscope head.
It also used to carry the microscope.
ARM
STRUCTURAL COMPONENTS
Supports the microscope and houses the illuminator.
BASE
OPTICAL COMPONENTS
Remagnifies the image formed by the objective lens;
standard magnifying power is 10x.
EYEPIECE/OCULAR
OPTICAL COMPONENTS
Holds the eyepieces in place above the objective lenses.
EYEPIECE TUBE
OPTICAL COMPONENTS
Primary lenses that magnify the specimen.
OBJECTIVE LENSES
A rotating turret that houses the objectives.
NOSEPIECE
A bigger wheel used to adjust the LPO in focusing
used also for initial focusing.
COURSE ADJUSTMENT KNOB
A smaller wheel for final focusing of the specimen using HPO and OIO;
used also to make the specimen more vivid.
FINE ADJUSTMENT KNOB
Where the slide/specimen is placed for focusing.
STAGE
It is used to hold the slide in place.
STAGE CLIPS
The light source of the microscope.
ILLUMINATOR
It is used to collect and focus the light from the illuminator on the specimen.
CONDENSER
It controls the amount of light reaching the specimen.
IRIS DIAPHRAGM
Moves the condenser up or down to
control the lighting focus on the specimen.
CONDENSER FOCUS KNOB
Magnification: 4x (RED)
SCANNER
Magnification: 10x (YELLOW)
It usually forms the general outline or wider portion of the object.
Low Power Objective (LPO)
Magnification: 40x (BLUE)
It is longer than the LPO and it forms a bigger image if the object is in focus.
In most cases, it is used to enlarge specimens that are so small under LPO.
High Power Objective (HPO)
Magnification: 100x (WHITE)
highest degree of magnification
It is used to examine stained smear preparations of microorganisms using immersion oil as their medium.
Oil Immersion Objective (OIO)
Calculating the Total Magnification
TOTAL MAGNIFICATION = Magnifying power of the eyepiece x Magnifying
power of the objective used
EXAMPLE:
Magnifying power of the eyepiece = 10
Magnifying power of the objective used = 100 (OIO)
Therefore: 10 x 100 = 1000x (The specimen in focus is magnified 1000
times its actual size using oil immersion objective)
