BIO130 Lab 1 Exercise 3 The Microscope
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Transcript of BIO130 Lab 1 Exercise 3 The Microscope
BIO132 Lab 1 Exercise 3 The Microscope
Parts of the Microscope, Light Adjustment, & Diopter
Magnification – enlarge
Resolution – separate into component parts
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 micrometer3. 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
100X Magnification
Line up the 0.0 line on the edge of the visible field: the zeros will no longer be visible
Read off where the ruler ends on the other side: this one looks like 1.745mm Each scope is a little different
400X Magnification
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
1860µm
Looks like 2 would fit across
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
1860µm
Looks like 2 would fit across
1860µm ÷ 2 = 930µm
New object:New object:
10X objective: diameter measured to be 1860µm
1860µm
Looks like 4 would fit across
1860µm ÷ 4 = 465µm
The green oval is approximately 465µm long
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.
10X objective: diameter measured to be 1860µm
1860µm
Looks like 4 would fit across
1860µm ÷ 4 = 465µm
465µm
40X objective: diameter measured to be 465µm
Looks like 1 would fit across
465µm ÷ 1 = 465µm
This object (green oval) is 465µm: you should get approximately the same answer which ever lens you use.
Dogfish Placoid ScaleDogfish Placoid Scale 4X objective(40X)
10X objective(100X)
40X objective(400X)
Measure one diamond
http://relentlessthirst.files.wordpress.com/2009/02/dogfish1.jpg
http://www.elasmodiver.com/Sharkive%20images/Spiny-dogfish-070.jpg
DinoflagellateDinoflagellate 4X objective(40X)
10X objective(100X)
40X objective(400X)
Don’t cut off his tails!
Red Tide
http://www.sciencedaily.com/images/2007/08/070830150106-large.jpg
http://www.pac.dfo-mpo.gc.ca/fm-gp/contamination/Images/Red%20Tide%20-%20Mary%20Mackin%202.jpg
Human Cheek CellHuman Cheek Cell 4X objective(40X)
10X objective(100X)
40X objective(400X)
Large irregular shaped cells: look like a ruffled sunny side up egg
Human Blood SmearHuman Blood Smear
WBC
RBC
4X objective(40X)
10X objective(100X)
40X objective(400X)
Tiny red dots, even with the 40X objective: guestimate carefully!
Dogfish Placoid ScaleDogfish Placoid Scale DinoflagellateDinoflagellate
Human Cheek CellHuman Cheek Cell Human Blood SmearHuman Blood SmearWBC
RBC