Microscope

• Micro (small)• Scope (view)

Three common types:1. Compound Light2. Stereo3. Electron (2 versions)

1. Compound Light• Most common• 2 lenses focusing at the same time

1. Ocular

2. Objective

• 2D image• High magnification through light

absorption

Parts of the microscope

Arm

Base

Term: Magnification

• Ratio of image size to actual size• Ocular: 10X

(“X” means times; for example, the ocular magnifies something 10 times)

• 4 objectives– Scan: 4X– Low Power: 10X– High Power: 40X– Oil immersion: 100x

• Multiply ocular x objective to get overall magnification

Field of View

Amount of object you can see• Decreases with increasing magnification

Depth of Focus

Thickness of specimen in focus at a given magnification

• Decreases with increasing magnification

• Lab says to make your own slide-we will use a prepared thread slide

Inversion Phenomenon

• Objects appear upside down and backwards in the compound microscope

• We will use prepared letter e slides

2. Stereomicroscope

• Used to get a better look at larger objects• 3D image• Specimen not mounted on a slide• Low magnification• Uses visible light through light scattering

3. Electron Microscope

• Uses electron streams focused by magnets to view specimens, not light

• 2 types1. Scanning

2. Transmission

Scanning Electron Microscope

• 3D images

• 1,000-10,000x magnification

• Resolution of 5 nanometers

pollen

microscope

Transmission Electron Microscope

• 2D

• 10,000-100,000 magnification

mitochondria

Wet mount

• Way to create a simple slide• Need a clean slide and a coverslip• Procedure

– Place specimen on slide– Add a drop of water– Place coverslip over specimen at an angle to avoid air

bubbles– Wipe away excess water– View under microscope

• Today: pond water wet mount