LightMicroscope
Microscope Parts:Microscope Parts:
a.Ocular lens (Eyepiece)
•used to look through
•has a magnificationof 10X
Microscope Parts:Microscope Parts:
b. Objective Lenses
magnification•Offer moremagnification
three•There are threelenses we will use inour class.
–Scanning Objective 4x–Scanning Objective 4x
–Low Power 10x–Low Power 10x
–High Power 40x–High Power 40x
Calculating Magnification:Calculating Magnification:
multiplyeye pieceobjective lens•Simply multiply the eye piecemagnification by the objective lensmagnification.
400x•EX: A 10x eyepiece X 40x objective = 400x
•Now try the other examples below!
Magnification:
Magnification
OcularLens
TotalMagnification
Scanning
4x
10x
LowPower
10x
10x
HighPower
40x
10x
40x
100x
400x
Microscope Parts Cont’d:Microscope Parts Cont’d:
eyepiecec. Body tube – holds theeyepiece
carryingd. Arm – used forgrasping when carrying
supporte. Base – support
turnsobjectivelenses.f. Revolving Nosepiece –turns the objectivelenses.
Microscope Parts Cont’d:Microscope Parts Cont’d:
platformg. Stage –platform on whichspecimen or slideis placed
holdh. Stage clips –hold the slide inplace
Microscope Parts Cont’d:Microscope Parts Cont’d:
large movement.low i. Coarse Adjustment(Large knob) – causeslarge movement. useunder low power
small movement high j. Fine Adjustment(small knob) – causessmall movement useunder high power
Microscope Parts Cont’d:Microscope Parts Cont’d:
k. Diaphragm
controls the amount– controls the amount oflight passing throughthe specimen
l. Light Source (illuminator)
lightthrough the object – provides the lightwhich must passthrough the objectto be studied
LightMicroscope
II. Microscope Safety:II. Microscope Safety:
twoarmbase Always carry the microscope with twohands - one on the arm and oneunderneath the base of the microscope.
touch the lensesDo not touch the lenses.
turnthe microscope off,If using a microscope with a light, turnthe microscope off, when not in use.
slide or coverslipNotify teacher if a slide or coverslip breaks.
III. Focusing Specimens:III. Focusing Specimens:
scanning1.Always start with the scanningobjective.
Coarse AdjustmentKnob2. Use the Coarse AdjustmentKnob to focus, image may besmall at this magnification
Focusing Cont’d:Focusing Cont’d:
LowPower (10x).3. Once you've focused onScanning (4x), switch to LowPower (10x).
Coarse AdjustmentKnobrefocus.4. Use the Coarse AdjustmentKnob to refocus.
Focusing Cont’d:Focusing Cont’d:
High5. Now switch to High Power.
Fine Adjustment Knob6. STOP!!!! At this point, ONLY usethe Fine Adjustment Knob to focusspecimens.
lightdarkdiaphragm.•If the specimen is too light or toodark, try adjusting the diaphragm.
reversedinverted•Images viewed under the lightmicroscope are reversed(backward) and inverted (upsidedown).
IV. Making a Wet Mount SlideIV. Making a Wet Mount Slide
thin Gather a thin slice/piece ofwhatever your specimen is.
ONE Place ONE drop of waterdirectly over the specimen.
coverslip45o anglegently let goPlace the coverslip at a 45o anglewith one edge touching the waterdrop and then gently let go.
How to Stain a Slide:How to Stain a Slide:
1.Place ONE drop of stain (iodine,methylene blue) on the edge of thecoverslip.
2.Place the flat edge of a piece of papertowel on the opposite side of thecoverslip. The paper towel will drawthe water out from under thecoverslip, and the cohesion of waterwill draw the stain under the slide.
Staining…Staining…
3.As soon as the stain has coveredthe area containing thespecimen, you are finished.