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Magnification Methods

Magnification involves increasing the appearance of a specimen or structure to allow a person to view it in greater detail. Resolution provides the viewer with a greater ability to see separate structures. Magnification devices, such as microscopes, create larger images many times the object's natural size using light, radiation and sound. The actual size of the object being viewed remains unchanged. Advances in magnification methods are highly valued - particularly in medicine and science.

Light Microscopy
- Light microscopy magnifies small biological specimens. Light is directed through the specimen by way of either a natural light source or an electric light. Light flows through the objective lens and the eyepiece, allowing you to view the specimen. A light microscope is useful for looking at bacteria, algae and protists. It is also practical for wet mounts when looking at living specimens. Maximum magnification achieved with light microscopy is about 1,000 times.
Electron Microscopy
- Electron microscopes emit electrons and X-rays.
  
  With electron microscopy, a specimen is magnified using electron emissions. The beam of electrons produces an image, allowing very tiny specimens to be viewed at high magnifications. Two types of electron microscopes exists. The scanning electron microscope, or SEM, transmits a 3-D image onto a monitor. A transmission electron microscope, or TEM, produces a 2-D image detected by a sensor. According to the Museum of Science, the SEM is capable of magnifying a specimen 200,000 times.
X-Ray
- Teeth and bones can be viewed with X-rays.
  
  Electromagnetic radiation magnifies certain physical structures, such as teeth and bones. According to the National Library of Health, bones appear on X-ray film because of density. Bones absorb most of the X-ray emissions and appear white. Metal and contrast dyes are white too, but air is black. X-rays go through skin directly into the body without being felt. However, electromagnetic radiation is dangerous at high levels.
Magnetic Resonance Imaging
- With an MRI, doctors can view cross-sectional portions of organs and structures.
  
  Using radio waves and an electromagnetic field, magnetic resonance imaging, or MRI, allows hundreds of magnified pictures of the internal organs to be taken non-invasively. MRI pictures show slices of structures, displaying more detail than with ultrasonography or X-ray. Sometimes a contrast dye is also used, allowing better viewing of organs. Doctors diagnose medical problems such as tumors, liver disease and obstructed blood vessels from MRI results.
Ultrasonography
- Ultrasound has been used medically for a long time.
  
  Ultrasonography is a technique useful for diagnosing medical illness. Ultrasonography uses high-frequency sound waves and electricity so that an image is produced and transmitted in real time. It is commonly done for monitoring pregnancies, diagnosing pneumothorax, pleural effusion and screening for cardiovascular disease. The New England Journal of Medicine reports that doctors have been using ultrasound for more than 50 years.

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