Tuesday, September 4, 2012

The advantages of optical microscopy

The microscope is an indispensable tool for biologists. optical biological microscope many biologists study is too small, the structure and function can not be seen with the naked eye. There are mainly two types of microscope: optical and electron microscopes. Optical microscope focused through the lens of the light, to create a magnified image, the electron beam and electron microscope focus electromagnet. Electron microscopy can resolve smaller objects, and advantages of the optical microscope.

Color and fluorescence
Electron microscope the use of electrons rather than photons, arising under an electron microscope image is black and white / gray scale (although the electron microscope images can be computer-enhanced to add color). On the contrary, optical microscopy, can provide color images of cells and cell structure. For example, in the past century, scientists have developed a variety of techniques to enhance the contrast of the image from the optical microscope, they can add the dye, combined with certain types of cells in the molecular (DNA, for example) and visualization of cell structure under the optical microscope. Connect to their fluorescence probe labeling of antibody molecules provides another intracellular structure, with an optical microscope to see. In recent years, scientists have also developed the technology, emphasis on "the reporter gene, gem microscope such as green fluorescent protein gene interests of a particular protein to become fluorescent. Biologists can track the protein in the cell to see it, what it does.

Specimen
The specimen must be carefully prepared before they can be observed by electron microscopy. In the process, they intended to kill the cells, and therefore can not be used for electron microscopy study of living cells. Conversely, many different types of optical microscope, can be used to view the cells are still living and operation, which is particularly useful when trying to understand certain aspects of cell biology. In addition, for the preparation of the specimens using electron microscopy techniques may create the image does not actually occur in real cells function.

Confocal microscopy
Confocal microscope, microscope accessories the laser beam to a specific depth in the sample is concentrated at one point. Testing equipment on a pinhole aperture to allow only light able to obtain clear images of a specific depth in a sample of a focal plane of focus reflect a biologist be included in the images, scanning the laser beam. Repeat this process to provide different depths of the capacity to establish a 3-D image of the specimen. The confocal microscope is a type of optical microscope.

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