Presentation on theme: "BIO130 Lab 1 Exercise 3 The Microscope"— Presentation transcript:
1BIO130 Lab 1 Exercise 3 The Microscope Parts of the Microscope, Light Adjustment, & Diopter
2Measuring 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 ocular40X Magnification
3100X MagnificationRead off where the ruler ends on the other side: this one looks like 1.745mm Each scope is a little differentLine up the 0.0 line on the edge of the visible field: the zeros will no longer be visible
5Using field diameter to determine the size of an object 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 1860µmLooks like 2 would fit across1860µm
6Using field diameter to determine the size of an object 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 1860µmLooks like 2 would fit across1860µm ÷ 2 = 930µm1860µm
7New object:10X objective: diameter measured to be 1860µmLooks like 4 would fit across1860µm1860µm ÷ 4 = 465µmThe green oval is approximately 465µm long
8Which 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.
910X objective: diameter measured to be 1860µm Looks like 4 would fit across1860µm ÷ 4 = 465µm1860µm40X objective: diameter measured to be 465µmLooks like 1 would fit across465µm ÷ 1 = 465µm465µmThis object (green oval) is 465µm: you should get approximately the same answer which ever lens you use.
10Dogfish Placoid Scale Measure one diamond 4X objective (40X)
14Large irregular shaped cells: look like a ruffled sunny side up egg Human Cheek Cell4X objective(40X)Large irregular shaped cells: look like a ruffled sunny side up egg10X objective(100X)40X objective(400X)
15Tiny red dots, even with the 40X objective: guestimate carefully! Human Blood Smear4X objective(40X)Tiny red dots, even with the 40X objective: guestimate carefully!10X objective(100X)40X objective(400X)WBCRBC
16Dogfish Placoid Scale Dinoflagellate Human Cheek Cell Human Blood SmearWBCRBC