Microbiology And Bright Field Microscopy
The Inseparable Fields of Microbiology and Bright Field Microscopy
The fields of microbiology and bright field microscopy have long been inseparable. When scientists first became interested in microbes, they had only very few tools to feed their curiosity and study the microbial world. What they had was a simple system of lenses and mirrors through which they could look at some bacteria or infected material. Today, even with the fields of molecular microbiology and DNA analysis developing rapidly and gaining even more popularity, bright field microscopy still remains as a laboratory technique to identify and characterize microbes.
Bright field microscopy is also one of the first fields that students of microbiology will find themselves immersed in. This is because many of the sophisticated concepts today arise because of knowledge acquired while studying microbes under the microscope.
What Can You See Under a Bright Field Microscope?
Microbiology is interested not only in bacteria, but in fungi, viruses, and other infectious agents such as worms, as well. Because microbiology relies so much on magnifying equipment, it has to constantly find ways by which microscopy can show even the minutest details of the microorganism of interest. Today, sophisticated microscopes such as electron microscopes can resolve details at the cellular level, allowing scientists to see even more of microbes than they ever have.
Bright field microscopy, however, has not gone out of fashion, and many microbiology students begin their studies by learning how Brightfield Microscopes work. In a nutshell, Brightfield Microscopes work by allowing light to pass through the specimen of interest, into a system of lenses, and to the eyes of the observer.
As such, magnification of a bright field microscope can at best reach a hundred times the original, and with the help of a drop of oil in between the lenses and the specimen. This oil prevents light from scattering out into the air, and can focus light rays directly into the lens, so that magnification is much higher.
Not all organisms, moreover, are visible under natural light. Many microorganisms are actually transparent, and the casual observer can miss them if they are not properly stained. Scientists have developed many different staining methods that will not only make microorganisms visible, but identify what proteins they might have as well.
For instance, in Gram staining, bacteria can be classified as either Gram positive or Gram negative. Gram positive bacteria appear purple under the bright field microscope after the staining process: these bacteria have thick cell walls, and also require certain antibiotics to be killed. Gram negative bacteria, on the other hand, will appear red or pink under the bright field microscope after the staining process: these bacteria have thinner cell walls, and will require another set of antibiotics to be killed.
Fungal spores are also visible under a bright field microscope, and these, in turn, need their own staining methods in order to be visualized. Although viruses cannot be magnified by a bright field microscope, their effects can be seen: when viruses escape a cell, they can cause it to rupture, an effect that you can see with proper staining and specimen sectioning techniques.
Scientists also use the bright field microscope to look at the effects of bacteria, viruses, fungi, or even worms on cells and cell systems. Some bacteria can weaken cell walls or cause cells to rupture. Some fungi can invade cells and cause certain morphological changes. Worms are easily seen under the microscope. For instance, scientists can look at blood samples under a microscope and point out bacteria, evidence of viral infection, worm eggs or cysts, and fungal spores.
What Can a Bright Field Microscope be Used For?
Because the bright field microscope can actually be powerful, it has many uses. In a basic microbiology laboratory, Brightfield Microscopes are routinely used to look at the effects of Gram staining on bacteria. Identifying bacteria begins with basic laboratory methods such as Gram staining, and many peer-reviewed journals do not accept molecular microbiology papers if they are not supported by such basic techniques first.
In a diagnostic laboratory, Brightfield Microscopes can be used to identify infectious microbes. Scientists can use blood, urine, or fecal matter as samples, place these samples on a slide, stain them, and then view them under the bright field microscope in order to see if any infectious organisms are present. Brightfield Microscopes can even be used in conjunction with special quantification slides: by counting bacteria present in a certain grid, scientists can calculate approximately how many bacterial cells are present in a sample.
In an ecology or food testing laboratory, Brightfield Microscopes can be used to identify any contaminating agents in water or soil. In conjunction with more sophisticated quantification and identification systems, scientists use Brightfield Microscopes to count how many microbes are present in samples, and what these microbes are.
These are only a few facts that link microbiology and bright field microscopy together. Science will always evolve to create better, bigger, and more complicated tools to study microbiology. However, bright field microscopy will always remain as an important laboratory tool.
