Microscope use Flashcards
important factors affecting image quality of microscope
enhancing resolution
contrast
resolution def
ability to see details clearly
contrast def
distinction between light and dark
microscopes on campus are
monocular compound light microsopes
monocular def
single eyepiece
compound microscope def
image on a slide will pass through more than one lens
ocular lens def
in eyepiece
objective lenses
selected from one of the objectives
mechanical stages feature
allow slides to be moved easily with knobs
parafocal feature
the images stay nearly in focus when objective lensees are switched
paracentric feature
once a sample is centered in the field of view, it will remain centered when switching to a higher magnification
brightness control knob def & function
on/off switch at base of microscope
turning it will increase illumination from light bulb
recommend- turn it to 3/4 to end point to avoid creating a field that is too bright to regulate
stage def
slide will be placed on this platform for viewing
slide holder and claw
claw needs to be opened to position slide
“X” & “Y” travel knobs
moves slide horizontally and vertically
ocular lens and magnification
magnifying lens in eyepiece
magnifies image by 10X
revolving nosepiece
disc is rotated when selecting and objective lens
objective lenses
magnifying lenses used to further magnify the image
magnification of each objective lense is
multiplied by 10, power of ocular lenses, to determine total magnification
red lense magnification
Lens Power Ocular Power Magnification
4X 10X 40X
yellow lense magnification
Lens Power Ocular Power Magnification
10X 10X 100X
red lense name
scanning
yellow lens name
low-power
blue lense magnification
Lens power ocular power magnification
40X 10X 400X
blue lens name
high-power
white lens magnification
lens power ocular power magnification
100X 10X 1000X
white lens name
oil immersion
order of magnification of lenses
red- scanning
yellow- low- power
blue- high-power
white- oil immersion
coarse and fine focus knobs function
used to adjust height of stage to bring the slide closer to the objective lens
coarse focus knob used with which lens
lower power lenses
coarse knob does
moves stage in larger increments than fine adjustment knob
coarse knob should not be used when
the two higher power lenses are in place
coarse and fine focus knob should never
be used at the same time
no two adjustment knobs should
be used simultaneously
iris diaphram def and function
lever located approx 1.5 in under stage
used to regulate the amount of light reaching the slide
substage condenser def and function
does not magnify
condenses image so it can be seen
substage condenser should not
be adjusted for routine use of microscope
as power of lens inscreases, resolution…
decreases
why does resolution decrease when power of lens increases
smaller surface area of stronger lenses
refraction of light waves as they pass between glass surfaces
use of oil immersion in between slides does what
less light refracted
image quality improves
immersion oil has almost the same refractive index as
glass, light behaves similarly when passing through both mediums
use of oil allows
to magnify specimen 1000X with some clarity
using 1000X lens without oil
very unclear image due to excessive light refraction
steps of use of highest power objective lens, oil immersion
- use nosepiece to postition scanning lens on one side of slide and oil immersion lens on other side
- apply drop of immersion oil to slide, using incoming ligth as target
- rotate nosepiece to click immersion lens in place over slide
- use fine focus knob and iris diaphragm to improve image
- can go back and forth between scannning power and oil lens to refine image
- immersion oil lens makes contact with drop of oil
if you lose focus with oil immersion go back to
scanning power, back and forth
