THE MICROSCOPEPRACTICAL NO (2)

DALIA KAMAL ELDIEN MOHAMMED

Light microscope

The optical microscope is the most common type of microscope used in the laboratory, contains several parts with specific functions:

1-STRUCTURAL COMPONENTS Arm: this part on the side of the microscope is used

to supports the microscope when carried. Base the bottom part of the microscope When carry the microscope one of your hand in the

arm, and the other under the base body

2-OPTICAL COMPONENTS Eyepiece: contains the ocular lens, which provides a

magnification power of 10x to 15x, usually. This is where you look through.

Nosepiece: holds the objective lenses and can be rotated easily to change magnification.

Objective lenses: usually, there are three or four objective lenses on a microscope, consisting of 4x, 10x, 40x and 100x magnification powers. In order to obtain the total magnification of an image, you need to multiply the eyepiece lens power by the objective lens power. So, if you couple a 10x eyepiece lens with a 40x objective lens, the total magnification is of 10 x 40 = 400 times.

Light source: it projects light upwards through the diaphragm, slide and lenses.

Condenser is used to collect and focus the light from the illuminator on to the specimen. It is located under the stage often in conjunction with an iris diaphragm.

Iris Diaphragm controls the amount of light reaching the specimen. It is located above the condenser and below the stage. Most high quality microscopes include an Abbe condenser with an iris diaphragm. Combined, they control both the focus and quantity of light applied to the specimen. As a rule of thumb, the more transparent the specimen, less light is required.

Coarse adjustment: this part moves the stage up and down to help you get the specimen into view

Fine adjustment: this part moves the stage slightly to help you sharpen or "fine" tune your view of the specimen

Illumination: The light source for a microscope. Older microscopes used mirrors to reflect light from an external source up through the bottom of the stage; however, most microscopes now use a low-voltage bulb.

Stage clips: hold the slide in place. Stage: it is a flat platform that supports the slide being

analyzed.

Parts of light microscope

How Does a Microscope Work? All of the parts of a microscope work together - The

light from the illuminator passes through the aperture, through the slide, and through the objective lens, where the image of the specimen is magnified.

The then magnified image continues up through the body tube of the microscope to the eyepiece, which further magnifies the image the viewer then sees.