Cycling of Matter in Living Systems

Development of Imaging Technologies

To be able to study cells and increase our knowledge of cells there had to be new developments in microscope technology and staining techniques

Microscopes were built to see the building blocks of life but cells are not easily seen unless something is done to them (ie staining or illumination)

Evolution of microscopy

Viewing through a water filled-glass sphereObserved magnification, but did not put it to

practical use

Ancient Greeks

Brief history of Microscopy

Two lens systemMagnification extending the reach of the

human eye

Janssen brothers (Dutch) 1590

Three lens systemMagnification allowing for the observation of

cells

Robert Hooke (British) 1655

Single lens system similar to a magnifying glass

Able to see moving microorganisms

Antoni van Leeuwenhoek (Dutch) 1673

Uses two or more curved lenses and a light source to magnify objects

Compound Light microscope

Modern Microscopy Technology

Uses beam of electrons to produce images with fine detail

Electron Microscopy

TEM-Transmission electron microscopeSEM-Scanning electron microscope

Types of Electron Microscopes

Provides information about molecules on the cell surface

Fluorescence Microscopy

Uses laser beams; the living, transparent cell can be viewed in 3D

Confocal Laser Scanning Microscope Technology

More magnifying power than an electron microscope

Produces 3D images of molecules such as DNA

Scanning Tunneling Microscope

Contrast enhancing techniques

Provides contrast for observing individual structures and kills cells

Stain

Ability to distinguish between two structures that are very close together

Resolution