BIO130 Lab 1 Exercise 3 The Microscope

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BIO130 Lab 1 Exercise 3 The Microscope
Parts of the Microscope, Light Adjustment,
Diopter
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• Measuring Field Diameter Using the Stage
  Micrometer
• 1. Insure that left ocular lens is turned fully
  counterclockwise
• (Lens should be as tall as it can be)
• 2. Focus on the stage micrometer
• 3. Measure the diameter (widest part) of the
  field of view using the tiny millimeter ruler of
  the stage micrometer using only your left eye in
  the left ocular

40X Magnification
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100X Magnification
Read off where the ruler ends on the other side
this one looks like 1.745mm Each scope is a
little different
Line up the 0.0 line on the edge of the visible
field the zeros will no longer be visible
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400X Magnification
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Using field diameter to determine the size of an
object specimen feature or cell 1. Know the
field diameter of the objective lens you are
looking through. (We measured this) 2. Center
and focus the object. 3. Guess how many of
that object would fit end to end across the
diameter of the field. (Diameter the widest
part of the circle of light you see through the
lens)
10X objective diameter measured to be 1860µm
Looks like 2 would fit across
1860µm
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Using field diameter to determine the size of an
object specimen feature or cell 4. Divide the
field diameter by the number of objects you
think would fit across end to end to determine
the size of one of the objects.
10X objective diameter measured to be 1860µm
Looks like 2 would fit across
1860µm 2 930µm
1860µm
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New object
10X objective diameter measured to be 1860µm
Looks like 4 would fit across
1860µm 4 465µm
1860µm
40X objective diameter measured to be 465µm
Looks like 1 would fit across
465µm 1 465µm
465µm
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Which lens do I use? The object is a fixed size,
regardless of lens you should get the same
answer! Use the lens that allows you to see the
whole object the best big enough to guestimate
how many fit across the diameter, not too
magnified that you cannot see the whole object
in the same field.
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10X objective diameter measured to be 1860µm
Looks like 4 would fit across
1860µm 4 465µm
1860µm
40X objective diameter measured to be 465µm
Looks like 1 would fit across
465µm 1 465µm
465µm
This object is 465µm you should get
approximately the same answer which ever lens
you use.
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4X objective (40X)
Dogfish Placoid Scale
Measure one diamond
10X objective (100X)
40X objective (400X)
A.W.Czura SCCC East
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http//www.elasmodiver.com/Sharkive20images/Spiny
-dogfish-070.jpg
http//relentlessthirst.files.wordpress.com/2009/0
2/dogfish1.jpg
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4X objective (40X)
Dinoflagellate
Dont cut off his tails!
10X objective (100X)
40X objective (400X)
A.W.Czura SCCC East
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Red Tide
http//www.sciencedaily.com/images/2007/08/0708301
50106-large.jpg
http//www.pac.dfo-mpo.gc.ca/fm-gp/contamination/I
mages/Red20Tide20-20Mary20Mackin202.jpg
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4X objective (40X)
Human Cheek Cell
Large irregular shaped cells look like a ruffled
sunny side up egg
10X objective (100X)
40X objective (400X)
A.W.Czura SCCC East
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4X objective (40X)
Human Blood Smear
Tiny red dots, even with the 40X objective
guestimate carefully!
10X objective (100X)
40X objective (400X)
WBC
RBC
A.W.Czura SCCC East
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Dogfish Placoid Scale
Dinoflagellate
Human Cheek Cell
Human Blood Smear
WBC
RBC