Compound microscopes are the most widely used microscopes commonly seen in school and research labs. They are utilized for observing and identifying cells and tissues because of their high magnification and lower costs. They provide better magnification than a stereomicroscope and cost less than the electron microscope, making compound microscopes ideal for learning and research. If you are keen on microscopes, let is tell you about the structure and how a compound microscope works.
What is a Compound Microscope?
Compound microscopes are high magnification microscopes typically used to examine live cells and tissues. While stereo microscopes cannot observe intricate details and electron microscopes do not examine living cells – compound microscopes are the solution to both issues. You can read more detailed differences here.
Compound microscopes have two lenses that work together to produce high-magnification images of the object. The light source brightens the specimen with the help of the condenser to focus the light properly onto the sample. The magnification typically ranges from 40x to 1000x, yet some models may go up to 3000x.
Structure of Compound Microscope
To understand the working of a compound microscope, it is important to recognize the parts of the microscope. Its structure is simple, yet it has multiple components that produce clear images. A compound micro consists of:
- Light source
- Objective lens
- Coarse focus
- Fine focus
- Dioptre adjustment
- Stage clips
How does a Compound Microscope Work?
Each of the compound microscope parts performs its specific function to give the image on the eyepiece. A slide with the specimen is prepared and placed on the stage. Stage clips keep the slide in place and prevent unwanted movement. When you plug in the microscope and switch it on, the light source illuminates the specimen. The condenser reflects the light which goes to the objective lens and produces an image on the eyepiece.
While the basic function of all compound microscopes is the same, the light source may vary from one type of microscope to the other.
Types of Compound Microscope
Biological microscopes are the most commonly used compound microscopes. They are mainly utilized to observe microorganisms and living cells. They are typically known as bright field microscopes or may have a dioptre setting. There are a few biological digital microscopes with LCDs like Celestron 44340. Most digital microscopes are unable to observe cells.
Phase Contrast Microscope
Phase contrast microscopes have the same assembly as a bright field microscope; besides that, they use a special phase contrast lens instead of the standard objective lens. The condenser is also specifically designed for phase contrast microscopes for clear observation. They are commonly used for observing bacteria, living microbes, and blood cells. You can further read the article Why do Biologists Prefer a Phase Contrast Microscope?
It is also known as a confocal microscope that uses different wavelengths on a dyed specimen to produce the resulting image. The images are then scanned and can be joined together to create a 3D image.
Polarising microscopes make sure of polarization and bright field microscopy to produce images. The analyzer and polariser cross-polarize the light to focus on the details of the specimens.
What can you observe with a compound microscope?
You can observe all kinds of biological specimens in the light microscope on a tissue level. The precision may depend on the magnification and resolution power of the microscope. A compound microscope allows you to observe cells, tissues, bacteria, and other similar specimens.
What is resolution?
Resolution is defined as the distance between two points on the specimen that can be distinguished from each other. The maximum resolution of a compound microscope is 0.2µm.
What is the maximum magnification of a compound microscope?
Compound microscopes come in various magnifications produced by the combination of two lenses. Eyepieces usually come in 10x and 100x, along with objective lenses collectively creating images. The common maximum magnification of light microscopes is 1000x, yet you may also find magnifications up to 2500-3000x.
What Brands are good to buy microscopes?
Can you take pictures through a compound microscope?
Yes, you can take pictures through a compound microscope by connecting a digital USB camera and observing it on a monitor or mobile screen. You can check M150C.
How much does a compound microscope cost?
Compound microscopes come in multiple types depending on their size, material, and magnification. You can find a compound microscope for as less as $100 up to $2000 according to their body structure and application. Some microscopes are even less than $100. Though they vary in quality, the microscope for less than $100 is great for learning purposes for young children. Microscopes that offer high precision may cost quite high.
The Bottom Line
Compound microscopes are widely used for biological research purposes and in schools to teach students about the working of microscopes. They come in different materials according to need and varying lens magnification. They work by focusing the light through a condenser that helps focus the image onto the eyepiece for observation. You can examine bacteria, cells, and tissues for research in biology, pharmacy studies, and geology.