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