2. Microscopy Flashcards
(16 cards)
What is the nose piece?
Contains the roast ting turret which houses the objective lenses. Rotate clockwise to click different lenses into place
What is the stage?
A mobile platform for the specimen slide. Slide is held in place by spring clips and usually placed eight the label to the right
What are the objective lenses?
Four lenses-
X4 scanning, X10 low power, X40 high magnification, X100 for oil immersion
What is the formula for calculating magnification factor?
Objective maginification x ocular magnification
What is the sub stage condenser?
Two lenses fitted below the stage that condense the light from the light source into the specimen.
Image becomes brighter, sharper and the position can be adjusted
What is the iris diaphragm?
This can be adjusted to regulate the amount of light that passes through the condenser
What is the Rheostat?
Alters the level of light produced by the light source
What is the Light source used for?
Allows illumination of the specimen
What is the Coarse focus and fine focus control?
Coarse- large knob
Fine- small knob
Both essentially to raise and lower the stage to allow the image to be focussed
What is the eyepiece used for?
Allows the specimen to be viewed.
Contained ocular lenses which magnify the primary image formed by the objective lens
What care and maintenance is there for a microscope?
- Do not place near a window or heat source
- Do not place near vibrations , liquids or draughts
- Keep free from dust
- Hold Lomb and support base whilst carrying
- Keep stage clean
- Oil moving parts as necessary
- Remove oil from lens using paper
- Remove samples when not in use
- PAT and servicing
How do you use a microscope?
- Remove dust cover, plug into socket
- Lower stage to lowest point
- Check rheostat is turned to low
- Switch on the light, turn up rheostat
- Inspect eyepieces, lenses and condenser- clean if needed
- Place slide on stage, ensure specimen is in the centre
- Rack the stage up as high as possible
- Adjust the distance between eyepieces until the two fields become one
- Slowly rack down whilst looking using the course focus
- Once image is in view, use fine focus to refine detail
- Adjust condenser for optimum light
What kind of light and magnification is needed for a blood smear?
High light.
X10, X40, then oil immersion
(Same for bacteria examination)
What kind of light and magnification is needed for ectoparasites?
Low light and Low power .
X4 and X10
What is the vernier scale?
The scale on the side of the microscope used to pinpoint exact specimen location on slides for future observation
How do you use the vernier scale?
- Align the area of interest in the exact centre of the field of view
- Read the vernier scale horizontal then vertical
- To Record, use the primary scale (top value) by recording the value to the left of the vernier scale (bottom) Increment 0 unless it is directly aligned.
