light microscopy sarah heintz. compound microscope the microscope uses a lens that is close to the...

Light MicroscopySarah Heintz

Compound Microscope The microscope uses a lens that is close to the object and uses light to focus on the real image of the object.

The use of an eye-piece magnification and the objective magnification allows for higher magnification, and exchangeable objective lenses magnify the object depending on the setting.

Has a variety of objective lens: 4X, 10X, 100X

A Modern Light Microscope Uses visible light to see an object.

High magnification

Types of Light Microscopes•Bright-Field Microscopes

•Dark-Field Microscopes

•Phase-Contrast Microscopes

•Differential-Interface-Contrast Microscope

•Fluorescence Microscope

•Confocal Microscope

•Dissecting Microscope

Bright-Field Microscope•Little contrast when viewing.

•Staining is required most of the time to see features of the specimen.

•Light is transmitted through the specimen.

Dark-Field Microscope•The field of view is dark while the specimen is light.

•The condenser lens focuses the light onto the specimen.

Phase-Contrast Microscope•The microscope transfers the phase shift in light to brighten the image of the specimen.

•It reveals more cellular structures than a bright-field microscope.

Differential-Interference-Contrast Microscope•Separates a polarized light source into two mutually coherent parts which are displaced. When they combine, the two beams produce a greater contrast.

Fluorescence Microscope•The fluorescence microscope transfer to one wavelength and emit it at another length.

•The illumination light is separated from the much weaker fluorescence through the use of an emission filter.

Confocal microscope•Only one part of the specimen is shown at once and all the other parts are excluded to prevent blurring.

•A pinhole is placed at the confocal plane of the lens to emit out-of-focus light and a laser scans the specimen.

Dissecting Microscope Is used for a low amount of magnification on a specimen.

Often used to observe solid surfaces of specimens

Things to remember… More advanced parts of the cells are not shown as easily with the light microscopes.