MicroscopyBy Jane Horlings

Microscopy

Robert Hooke, circa 1700s Electron Microscope, late 1900s

Early light microscope (UL), drawing by Hooke (LL)

Light Microscopes

Light Microscopes

Dissecting (stereo) microscope (L), compound microscope (R)

Light Microscopy; Plant Cells

Onion root tip, cell division (L), shoot tip (R)

Light Microscopy, Phase Contrast

Single celled Amoeba dividing (L), green alga Micrasterias (R)

Phase contrast

Fluorescence

Confocal

Light Microscopy

Electron Microscopes

Limitations of Electron Microscopy

• Works in a vacuum• Specimens are dead,

chemically preserved; no life processes can be seen

• No color (colorized by artist on computer)

Electron MicroscopesTransmission Electron Microscope (TEM)

Scanning Electron Microscope (SEM)

Scanning Electron Microscopy

SEM of cilia

TEM of cilia

Bacterium

RBCs in clot

SEM

Mite (UL)

Gecko toes (LL)

Shark skin (LR)

SEM

Red blood cells and Trypanosoma (L), Giardia (R)

SEMTrypanosome

Red blood cells

Transmission Electron Microscopy

SEM of cilia

TEM of cilia

Viruses (L), animal cell (R)

TEM

Animal cell (L), muscle tissue (R)

TEM

Light Microscopy

• Based on light• Specimens can be

alive; life processes can be seen

• Color; dyes may be used

Parts of the Microscope

• Ocular lenses

• Objective lenses

• How to compute the magnification

Use of the Microscope

• Place slide in center• Adjust light, lenses, barrel

– Put on low magnification!– Move stage all the way up

and then back down half a turn!

Use of the Microscope

• Look and readjust focus

• Move to higher magnification if needed

Use of the Microscope

• Importance of focusing with the fine adjustment!

• Oil immersion lens

• How to adjust the light

End