Types, Parts and Uses of Inverted Microscopes
The development of the first real microscope, an optical instrument that enlarges the image of any object, in Holland around 400 years ago has enabled scientists to study objects that would not have been visible to the naked eyes.. This has greatly aided in the discovery and study of what were previously called ‘mysterious’ components of living things that led to advances in science. Through the years, there were a lot of improvements in the field of microscopy. The development actually started from the lens makers who used their lenses to magnify certain objects illuminated by a light source in the microscope. Now, aside from the light microscope, there are other types of microscopes like the scanning electron microscope ( SEM ) and the transmission electron microscope, However, this article covers only the light microscope.
Light Microscope Parts
For a better understanding of this article, it is best to know the different basic parts of a microscope. Take note that only the basic parts are listed below.
1 .Specimen holder control
- Stage- the platform where the specimen is placed
- Clips- used to hold the specimen firmly on the stage.
2. Illumination
Light on the specimen. The system consist of the lamp, rheostat and the condenser.
3. Lenses
- Objective lens - the lens near and that gathers light from the specimen
- Eyepiece lens - the lens used to look at the specimen.
- Nosepiece - rotating mount that holds the objectives.
4. Focus
Used to put the specimen into the proper viewing distance from the objective, adjusted through the coarse and fine focus knobs.
5. Arm
Holds all the objective
6. Base
Supports the weight of the microscope
Types of Microscope
A. Based on lenses
The two basic types of light microscope are the stereo and the compound microscopes. A stereo microscopes is the most used type, where a three-dimensional image of the specimen is seen. A disadvantage of the stereo microscope is its low resolution and magnification.
The compound microscope gets its name from the fact that magnifies the specimen through the objective and the eyepiece. It is used when a higher resolution and magnification are needed and not a 3-D image.
Actually, the stereo microscope also has objective lenses and an eyepiece but among the users of these instruments, the word microscope refers to a compound microscope. A stereo microscopre is called stereo microscope.
B. Based on Frame types
1. Upright Microscope
The most used type, the objectives are above the specimen.
2. Inverted Microscope
In this type, the objectives are positioned below the specimen. There are two sizes of inverted microscopes: the routine and research. The two differ as follows:
- Routine Inverted Microscope
This is smaller and has limited uses than the research microscope. May not have fine focus adjustment, may not accept cameras and is for low to medium powers only
- Research Inverted Microscope
This is large and expensive but with more capability than the routine microscope. Designed to do almost anything expected in a microscope. Capable of being attached with a camera for better documentation
Uses of the Inverted Microscope.
After knowing where the inverted microscope stands among the different types of microscope, where does one choose to use an inverted microscope? The following are instances when an inverted microscope is appropriate:
1. When the specimen is large that the objective is likely to touch the specimen as they are moved to try different magnifications.
2. When viewing thick specimens like cells and tissues in transparent petri dishes or culture containers. The lenses can get close to the bottom of the specimen container without touching it.
3. When the specimen is pulled down by gravity that it is immersed at the bottom of the holder or dish. An inverted microscope would view the specimen directly at the bottom of the container.
4. Viewing the specimen at the bottom allows the use of dish covers to prevent drying up and contamination
The inverted microscope is suitable in viewing samples in biological laboratories in research institutes, educational institutions,hospitals, and agricultural projects. The inverted microscope is also used in transparent semiconductor devices and gemological samples. This type of microscope has provided the means to improve handling of specimen, like avoiding unnecessary movements when the objectives are changed. Nearer contact with the specimen improves the clarity of the image.
As more improvements are made in microscopy, scientists are provided with better tools to discover more for the betterment of mankind. A lot of discoveries that benefited mankind especially in health care were arrived at with the aid of a microscope.