Quiz Microscopy Flashcards
1
Main switch on/off
2
Brightness adjustment knob
3
Light-path_ selection-knob.
4
Specimen holder
5
Y-axis knob and x-axis knob
6
Revolving nosepiece
7
Coarse focusing knob and fine focusing knob
8
Binocular portion
9
Diopter adjustment rings
Lo
Aperture diaphragm lever
11
Fitter holder (for darker observation)
12
Filter C the filter of 45mm in diameter can be inserted)
Description of the microsvcope.
A microscope is a magnifying glass.
A microscope is a magnifying glass
The compound light microscope ( brightfield microscope) the type use in most clinical laboratories consists of two magnifying lenses:
The objective and the eyespieces (ocular)
The total magnification observed is the product of the magnifications of these two lenses.
Resolving power is the limit of usable magnification.
Resolution indicates how small and how close individual objects ( dots) can be and still be recognizable.
Numerical aperture (NA) is an index or measurement of resolving power.
the light gathering ability of a microscope objective is quantitatively expressed in terms of the NA, which is a measure of the number of highly diffracted image forming light rays captured by the objectgive. Higher NA values allow increasingly oblique rays to enter the objective front lens, producing a more highly resolved image.
Focal length
is the distance from the object being viewed to the lens or the objective.
the magnification and NA are inscribed on each lens as a number.
parts of the mictoscope
Framework
Base
Arm
Stage
Parts of the Microscope
Illumination system components
◦Light source, intensity control, types of bulbs
◦The condenser directs and focuses the beam of light from the bulb onto the material under examination.
◦The aperture iris diaphragm is located at the bottom of the condenser, under the lenses but within the condenser body. By opening or closing the aperture iris diaphragm, you let more or less light into the field of view.
◦A field iris diaphragm is also present in better microscopes.
. Magnification system components
Ocular is the eyepiece, a lens that magnifies the image formed by the objective.
◦Objectives: achromatic and planachromatic,
low-power (10X),
high-power (40X), and
oil-immersion (100X).
◦Objectives are responsible for primary image formation and help determine the quality of images the microscope is capable of producing.
Focusing system
Interocular adjustment, left ocular adjustment, body tube motion: coarse and fine
Passage of Light in Microscope
Lamp condenser
Lens projects an image of the light source onto the plane of the condenser diaphragm.
Ocular lens
The eyepiece magnifies the image created by objective lens a second time and creates an image as if viewed close to the eye.
Objective lens
Gathers light passing through a specimen and projects image into the body tube, the beginning of the magnification process.
Substage lens system
Once light has passed through the lamp condenser and the field diaphragm, it passes through the condenser aperture and lens system below the specimen stage. The substage condenser concentrates light onto the specimen.
Brightfield Microscopy
Brightfield illumination is
the common type of illumination for general laboratory work.
•Because the microscope is such a precision instrument and an important piece of equipment, it must be kept in excellent condition, optically and mechanically. It must be kept clean and aligned.
Care and Cleaning of the Microscope
◦Cleaning the microscope exterior
Gauze or soft cloth moistened with cleaning agent, rubbed in circular motion, and dried immediately with Kimwipe.
Cleaning optical lenses and oculars
◦Cleaning the objectives
Only use lens paper- NEVER KIMWIPES
Always begin with the 10X then 40X then Oil-immersion (100X)
Cleaning the condenser
First blow away dust, lint, and dirt with an air-syringe. Polish the light source and condenser with lens paper only- KIMWIPES
Cleaning the stage and adjustment knobs
Clean after each use with gauze or Kimwipe. Make sure all parts are dry.
Maintenance and Storage of the CX33 Microscope 1
- Do not leave stains or fingerprints on the lenses and filters. Cleaning is performed by gently wiping the lens or filter with a piece of clean lens paper (NEVER KIMWIPES).
Maintenance and Storage of the CX33 Microscope 2
- Wipe the portions other than the lens with a dry soft cloth (piece of gauze).
Maintenance and Storage of the CX33 Microscope
3.
- Store the microscope in a dry place or cover it with the dust cover.
Alignment
When properly aligned, the microscope is adjusted in such a way that the light path through the microscope, from the light source to the eye of the observer, is correct.
Light adjustment
Light adjustment is made before any focusing is done. The power supply is turned on and the light intensity adjusted to a bright but comfortable level. Light adjustment is further accomplished by raising and lowering the condenser and opening and closing the aperture iris diaphragm.
Focusing
Coarse adjustment is first, then fine adjustment and additional light adjustment.
Other Types of Microscopes
(Illumination Systems)
Darkfield microscope
◦Uses scattered light to view objects that appear light on a dark background
Other Types of Microscopes
(Illumination Systems)
Differential interference-contrast microscope
◦Gives objects a three-dimensional appearance
Electron microscope
◦Provides greater magnification and resolution than conventional light microscopy
◦Two types: transmission and scanning electron microscopy
Other Types of Microscopes
(Illumination Systems)
Electron microscope
Provides greater magnification and resolution than conventional light microscopy
◦Two types: transmission and scanning electron microscopy
Other Types of Microscopes
(Illumination Systems)
Fluorescence microscope
◦Used to observe molecules that fluoresce, such as molecules coupled to antibodies for specific fluorescent labeling
Other Types of Microscopes
(Illumination Systems)
Phase-contrast microscope
Used to increase the contrast in unstained specimens, such as a waxy cast in a urine specimen
◦The microscopist must be proficient in changing from brightfield to phase contrast, because in a given specimen, some structures are better visualized with phase contrast and others with brightfield.
Other Types of Microscopes
(Illumination Systems)
Polarized and compensated polarized microscopes
Used to identify crystals in body fluids (such as synovial or joint)
◦As light passes through the specimen, some objects (such as crystals) can rotate the light.
◦An object that polarizes bends light so it can be visualized when viewed through crossed polarizers.
◦A compensator is added in compensated polarized microscopes to help differentiate certain crystals and for other applications.
Digital Microscopy
Digital microscopy automatically locates and pre-classifies blood cells into categories; it digitizes images for electronic retrieval and sharing.
Digital cell morphology
◦New systems allow for remote review of a smear and storage of up to 20,000 slides with images in a database.
◦https://www.cellavision.com/en/
