Microscopy Flashcards
Describe the part of a microscope:
Ocular lens
The ocular lens contributes to the magnification. Usually 10x. It is contained within the eyepiece of the microscope.
Describe the part of a microscope:
Eye piece
Connects the ocular lens to the body tube.
Describe the part of a microscope:
Body tube
The body tube is hollow space containing mirrors. Light is reflected through it to the eye pieces.
Describe the part of a microscope:
Rotating nosepiece/ocular housing
The nosepiece is attached to the other end of the body tube. The nosepiece can rotate to allow the use of four different objective lenses.
Describe the part of a microscope:
Scanning lens
The scanning lens is the one you start with.
It has a lowest power of 4x.
Describe the part of a microscope:
Lower power lens
The low power lens has a power of 10x.
Describe the part of a microscope:
High power lens
The high power lens has a power of 40x.
Describe the part of a microscope:
Oil immersion lens
The oil immersion lens has a power of 100x.
Immersion oil must be used with this lens to prevent scattered light from causing a blurry image.
Describe the part of a microscope:
Mechanical stage
The mechanical stage supports the specimen slide.
Describe the part of a microscope:
stage clips
Holds the slide in place on the stage.
Also called slide holder.
Describe the part of a microscope:
Mechanical stage control
two knobs hanging from the bottom of the stage for moving the stage left and right, closer, or farther away.
Describe the part of a microscope:
Arm
The arm connects the body tube of the microscope to the base.
Describe the part of a microscope:
Lamp
The lamp provides illumination and the intensity of light is controlled by the rheostat.
Describe the part of a microscope:
Rheostat
The rheostat controls the amount of light emitted by the lamp.
What is the purpose of the condenser?
adjusts the light to improve contrast of the image
Describe the part of a microscope:
Condenser
The condenser bends the light to focus on to specimen.
What are the markings on the iris diaphragm used for?
to keep the amount of light consistent for switching between lenses
Describe the part of a microscope:
Iris diaphragm
an aperture to adjust the amount of light passing to the sample.
Describe the part of a microscope:
Coarse focus
the outer ring of the focus raises and lowers the
stage in large increments.
Describe the part of a microscope:
Fine focus
The fine focus knob raises and lowers the stage in small increments.
When is the coarse focus used?
The coarse focus knob is only used with the scanning(4x) objective.
Describe the part of a microscope:
Base
The base supports the microscope.
With which objective lenses is oil used?
Only the 100x, the oil immersion lens!
What is the range of viewing resolution via the microscope?
from 100 micrometers down to 1
As a rule of thumb, light microscopes are used for what?
viewing cells,
studying bacteria,
tissue analysis.
Name the factors that contribute to the quality of a microscope.
there are three
magnification
resolution
contrast
Briefly define:
Magnification
refers to the increase in apparent size of the image.
Briefly define:
Resolution
refers to the ability to distinguish fine detail.
(aka or resolving power)
Briefly define:
Contrast
refers to the ability to distinguish objects such as cells, from the background.
The goal of microscopy
is to create a magnified image of objects too small to be seen with the eye alone.
Brightfield microscopes use a combination of what to view a specimen?
glass lenses and light
Fields of study where a microscope is a necessary tool include
Cytology
Histology
Microbiology
Pathology
Briefly define:
The field of view
is the amount of the slide you are able to see through the eyepiece.
Briefly describe:
Total magnification
is the overall enlargement of the image of a specimen.
Briefly describe oil immersion.
oil immersion is when a drop of immersion oil is added to the slide, contacting both the sample and objective. With this oil, less light is lost into air or scattered by the slide, increasing resolution.
Briefly describe use of oil immersion as it relates to objective lenses.
Immersion oil can only be used with the 100X objective lens. The oil must be properly removed before using the 4X, 10X, or 40X objectives lenses.
