Microscope

Understanding Microscope' function is easy a Microscope is to microbiology as a telescope is to astronomy in physics. There are basically two basic types of microscopes. Light microscopes and Electron microscopes. Light Microscopes are the one that is mostly used in the biology laboratories of schools and colleges. Light Microscopes are known to magnify objects up to 1,000 times. Users see directly the images through the lenses of a Light Microscope. With reasonably powerful light microscopes you can have a clear view of most algae, fungi, and protozoa.

With a high-quality light microscope bacterial cells can also be viewed. However they are not suitable for viewing viruses as these tiny objects are even smaller than a wavelength of visible light which is about 0.2 microns. Light Microscopes are also not suitable for detailed examination of the individual tiny parts of cells.

For viewing extremely tiny objects Electron microscopes are the only solution. In Electron microscopes streams of electrons are used instead of light for the creation of images. Unlike Light Microscopes users see the picture generated by the electron microscope on a TV or computer screen. Electron microscopes are generally of three types. They are Transmission electron microscopes (TEM), Scanning electron microscopes (SEM) and Scanning-tunneling electron microscopes (STM).

Buying a Microscope
Buying a Microscope is not an easy task. Often it has been seen that a Microscope is purchased solely on the magnification it provides and not on what it is to be used for. This simple buying tips can be of some advice on how to choose the microscope of your choice.

• Understand Your Needs :The most basic criteria in choosing a Microscope is understanding clearly what is one going to study. If the work involves studying fossils, insect specimens, leaves, flowers, rocks, mechanical parts, etc for this extreme magnification is not needed. What matters is the room under the microscope for observing them. An excellent product suited to this type of application is a Stereo Microscope. A Stereo Microscope can also be used for dissection and offers excellent value to beginners, hobbyists along with some serious applications. The user-friendly Stereo Microscope gives an upright image and there is no need to prepare slides.
  
  If the need is to observe microorganisms like cells, pollen, etc then there is need for higher magnification. Along with that you also need to prepare a glass slide to observe them. A Compound Microscope is the most perfect tool for this type of criteria. A Compound Light Microscope helps in studying very small subjects and well suited to science or classroom applications.
  
  Then there is the Projection Microscope which is most suited for group discussion as well as for teaching.
  
  
• Frame of the Microscope :A Microscope is available in two basic frame types namely upright and the inverted. Out of the two, upright microscope is most prevalent in usage. In an upright microscope, with the objectives the specimen is looked down. Whereas in the Inverted Microscope there is looking up at the specimen. Inverted Microscopes are designed for use where the specimen size is very large or heavy or there is influence of the gravity. Though everything is under the influence of gravity but some things like cells in suspension get more influenced. Inverted microscopes are great for looking through thick specimens, like dishes of cultured cells. As the lenses can get very closer to the bottom of the dish, where cells growth takes place.
  
  
• Magnification, Focus and Light : It is the magnification, focus and light that makes a microscope work. Magnification is essentially a combination of the correct eyepiece with objective lens within practical limits. Extreme magnification is heavily dependant on optical quality and proportionally it gets more hard to use. Usually for most of the types of applications a 200x magnifying power is enough.
  
  Coming to focus. A practical microscope have two focusers namely coarse and fine. While low magnification is comparatively simpler but high magnification needs a finer touch for achieving focus.
  
  Lastly coming to light source. LED lights are not preferable as a microscope light source. A mirror or built-in illumination will do but it must have a proper way to control the amount of light. This is critical as many subjects do not require or even shies away from extreme illumination.
  
  
• Observing Stage : All microscopes feature slide holders. The slide holders help in keeping the specimen or prepared microscope slides steady. For lower magnifications, stage clips can suffice. For high magnification applications, a mechanical microscope stage is required as there is need to move the subject in slight increments.
  
  
• Monocular or Binocular : Another vital consideration is using one or two eye. Generally for all practical applications, a monocular head works fine. However, for lengthy observations eye fatigue should be considered. For this a Microscope with a binocular viewing head may be considered.

Microscope Accessories
Microscope Lamp
Low voltage Microscope lamps are excellent as general purpose illuminators. They are used for microscope or other miscellaneous laboratory work. A Microscope lamp is generally used on the bench top for illuminating subjects under the microscope orsometimes for providing illumination into the mirror located below the microscope stage. The Microscope lamp shown here is housed in a tapered metallic case. It features a diffusion screen along with a height adjustable stand rod.

Mechanical Stage
Mechanical Stage is the platform for holding the slide. Mechanical stages are better in comparison to plain stages as they can make a two-way fine movement. Mechanical stages can be single layer and double layer. Double layer mechanical stages can move more smoothly and hold two standard slides for comparing two specimens.

Microscope Slides
Microscopic slides are excellent tools having use in use in all types of biological laboratories that includes clinical, research, education.