compound light microscope

by vthigpen
Last updated 10 years ago

Life Science

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compound light microscope

When observing a specimen by transmitted light, light must pass through the specimen in order to form an image. The thicker the specimen, the less light passes through. The less light that passes through, the darker the image. Therefore, the specimens must be thin (0.1 to 0.5 mm). Many living specimens must be cut into thin sections before observation.

Ever since their invention in the late 1500s, light microscopes have enhanced our knowledge in basic biology, biomedical research, medical diagnostics and materials science. Light microscopes can magnify objects up to 1,000 times, revealing microscopic details. Parts of a Light Microscope•stage - where the specimen rests •clips - used to hold the specimen still on the stage Illumination - shed light on the specimen such as a light bulb or a mirror diaphragm- placed in the light path to alter the amount of light that reaches the condenserobjective lens - gathers light from the specimen eyepiece - transmits and magnifies the image from the objective lens to your eyenosepiece - rotating mount that holds many objective lenses tube - holds the eyepiece at the proper distance from the objective lens and blocks out stray lightFocus - position the objective lens at the proper distance from the specimen coarse-focus knob - used to bring the object into the focal plane of the objective lens fine-focus knob - used to make fine adjustments to focus the image Support and alignment •arm - curved portion that holds all of the optical parts at a fixed distance and aligns them base - supports the weight of all of the microscope parts

Four Main Types of MicroscopesOptical Microscopes-simplest types of microscopes. They use the theory of lenses to magnify the image generated by the passing of waves through the specimenElectron Microscopes-use beams of electrons to generate images instead of light. These microscopes are designed for high magnification. Scanning Probe Microscopes-physical probes are used in close contact to the sample and this generates a micrograph.Point Projection Microscopes-ions are excited from a specimen shaped like a needle and they hit a detector. The most modern type of this microscope produces 3-D images.


QuestionsWhat are the uses of microscopes?Why are some lenses made up of several lenses?What are the four types of microscopes?Whare are the 10 main parts of a compound microscope?

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