microscope date: 10/19/06 objectives: identify parts of the microscope and how to properly focus
TRANSCRIPT
Microscope Date: 10/19/06
Objectives: Identify parts of the microscope
and how to properly focus.
Parts of Microscope: • 1. Eyepiece 9. Fine-adjustment knob• 2. Stage 10.Coarse-adjustment knob• 3. Diaphragm 11.Nosepiece• 4. Light source 12.Objective lens: low
power • 5. Base 13.Objective lens: high power• 6. Tube 14. Diaphragm lever
• 7. Stage clips 15. Arm• 8. Opening to stage (aperture)
Microscope PartsKnow these parts are pay the
price!
15
2
89
105
1
4
11
6
12
13
714
3
Calculate Magnification:
Eyepiece (tube): 10x magnification• Objective lenses: 4x 10x 40x• Multiply the tube (10x) times the
objective lens to get • total magnification.• Possibilities:40x 100x 400x• You do not want to make him
angry • So study these calculation
Calculate Magnification:•Examples:•Looking at something under the •high power objective lens. What
would the total magnification be? ___________
•Looking at something under the low power objective lens. What would the total magnification be? ____________
Rules of the Microscope
Always start with Low Power & Coarse-adjustment- it’s easier to find and focus, then use fine-adjustment
On High Power (400x) we only use the Fine-adjustment focus. Never use coarse adjustment on high power!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
• *To clean lens: Use lens paper; don’t spit on it or use paper towels.
If You can Not Follow these rules you will answer to Him!!!!!!!!!!!
No Joke
MICROSCOPE KEY TERMS:
Field of View: How much of the slide you see.Magnification: The ability to enlarge a specimen. Millimeter: Unit of length - thickness of pencil lead.Field of View: Round circle of light; gets smaller as magnification increases.Prepared slide: Made in a lab; specimen is not livingWet mount slide : Made by you; specimen is alive.
To Focus: • Low power/scanning here in school
• Focus clearly (using coarse 1st, then fine)
• Switch to Medium Power (school low power)
• Sharpen focus (coarse, then fine)
• Switch to High Power
• Focus fine only
Types of Microscopes•Compound Light•Electron Microscopes: (1000x
greater than light mic.)•Transmission Electron
Microscope (TEM) 1,000,000x•Scanning Electron Microscope
(SEM) 200,000x•Scanning Probe 10 million
times
Compound Light Microscope• Brightfield / Darkfield Microscope -
can go up to: 2000x (School 400X)• Brightfield: • · bright background• · most often used in lab• Darkfield• · details more visible than bright• · dark background
Electron Microscopes: (1000x
greater than light mic.)
• · lenses made from electromagnets
• · gather and focus beam of electrons
• · electrons produced from heating a filament
• · can only be used on dead specimens
Transmission Electron Microscope
(TEM) 1,000,000x
•aims a beam of electrons through a specimen
• (thin)•shows the internal (inside)
structure in great detail
Scanning Electron Microscope (SEM)
200,000x sweeps a beam of electrons over
a specimen’s surface produces realistic 3D images• * shows surface in great detail•
Scanning Probe 10 million times
•* has a cantilever with a probe at the end
•* moves over the object and actually sees the atomic and molecular levels – object can be live…
Types of Microscopes Paper
•Close your Eyes Because this is Some scary stuff