Microscope Flashcards
What is the most common type of microscope used in a clinical laboratory?
binocular compound microscope
binocular - 2 pieces
compound - uses a combination of lenses to generate an image
What is a binocular compound microscope used for?
to evaluate blood, urine, semen, bodily fluids, feces and other specimens
How many microscopes should there be in a clinical laboratory (ideally)?
2 - one for parasitology and another for hematology + cytology
Why should there be a separate microscope for parasitology samples?
Reagents are used to examine parasitology slides which can be corrosive over time and cause damage
What are the parts to a microscope?
eye pieces (ocular lenses), nosepiece, objective lenses, stage, slide holder, travel knobs/mechanical stage knobs, fine adjustment knob, course adjustment knob, condenser, diaphragm, light source
What are ocular lenses?
- first point of magnification
- 10x power of magnification
- Can be focused for the individual
- Can be moved closer together or farther apart
- Some contain a small arrow to “point” to things
- Some contain a reticle
What is a reticle?
- a scale used to measure objects
- to use to determine the size of the specimen (esp. in parasitology)
what are objective lenses?
- second point of magnification
- contains 3-4 objectives typically, they revolve around the nosepiece
4x magnification
scanning
red
10x magnification
low power
yellow
40x magnification
high dry
blue
100x magnification
oil immersion
white/grey
How to calculate total magnification
Total Magnification = Ocular lens power X Objective lens power
How does an object appear when looking through a microscope?
the object will appear upside down and reversed
the right side is seen on the left
the left side is seen on the right
The movement of the mechanical stage is _______.
reversed
when moving the stage to the left, the object appears to the move to the right, vice versa
what is the microscope stage?
- this is where the slide is placed
- there is an arm to hold the slide
- there are control knobs that helps to move our slide back and forth, to use to scan
- some stages will have markings which allows you to mark and take note of where the slide is, both vertically or horizontally
What are the adjustment knobs on a microscope?
- these knobs move the stage towards or away from the objective lenses
- use to focus the specimen
what are the two types of adjustment knobs?
coarse adjustment knob
fine adjustment knob
coarse adjustment knob
moves the stage the most
brings the specimen into focus
use this w/ your smaller power objectives
fine adjustment knob
fine tunes and increases the details of the specimen
can be used w/ any of the objectives
moves the stage with the slightest possible shift
condenser
- sits below the stage (substage)
- it has 2 lenses that focus light from the light source onto the specimen being viewed
- light is focused by raising or lowering the condenser
- typically best if the condenser is kept at its HIGHEST position (closest to the specimen)
- W/O this - there are halos and fuzzy rings that can appear around the specimen
Diaphragm part of the microscope
- typically an iris type
- controls the amount of light that is directed up at the slide
- more light typically clarifies the specimen
- lower light will increase the contrast (best for identifying eggs in parasitology)
Light source of a microscope
- found at the base
- should be on a “dimmer” like switch –> meaning we should be able to control the intensity of the light and it depends on what your looking at
What are some ways to care and maintenance the microscope?
1) use only HIGH quality lens paper to clean the objective lenses (if not, scratches can form)
2) avoid excess oil when using the 100x objective
3) never use oil on any other objective
4) use lens cleaning solution (or methanol) to remove excess oil + clean objectives
5) place/store away from sunlight, drafts, liquid, and avoid excess heat & humidity
