Biological Tissue Observation Using Phase Contrast Microscope: The Different Techniques
There are many ways to examine tissue cultures. One of them is through the use of a microscope, a very powerful scientific instrument that allows you to see bacteria and other microorganisms not visible by the naked eye. It’s also possible to have biological tissue observation using phase contrast microscope.
How to Observe Bacteria-Bearing Tissues
Experts do agree that examination techniques of bacterial tissues with the use of phase contrast microscopes can give the most desired results. They are, of course, not perfect, but they can actually provide more enhanced as well as detailed images. Bacterial study is known to be very essential in the fields of biology and medicine. This allows doctors and scientists to understand the nature and origin of illnesses and hopefully find the appropriate cure for them.
Optical Contrast Techniques
You can use the different optical contrast techniques so bacteria can become more visible. These could either be through differential interference contrast or phase contrast. The former can produce 3D relief images of the specimen. The latter, however, is known to be much better since it can highlight the difference of the thickness of the specimen with the aid of phase differences of light being transmitted. Those microscopes that are not capable of producing phase contrast per se can still employ this method by using phase contrast lenses.
Examination Techniques of Bacteria with Phase Contrast Microscopes
Perhaps you can do a little experiment. You can try to get a little amount of tissue somewhere in your body. However, skin tissue may be advisable as they’re most exposed to bacteria.
1. Place the tissue specimen on the glass slide.
2. Before you lower the cover slip atop the slide, add a drop of water. This is a process called wet mount. This is in comparison to dry mount which allows you to observe the specimen without the need of adding water.
3. Observe the different types of microorganisms you can see under the phase contrast microscope. While you are observing, note how the bacteria appears differently from the other cells such as your skin cells. Their sizes, for one, can set the difference since skin cells are larger than bacterial cells.
Comparing Living Cells in Bright Field as well as Phase Contrast Illumination A living cell examined under brightfield illumination can appear almost transparent. Highly refractive areas—and very visible—can include the nucleus, membrane, as well as unattached cells, both spherical and rounded. If it is observed under various phase contrast optical accessories, almost similar field of view can give more sophisticated and clearer detail of the structure. Attachments to the cell become more identifiable as well as its internal structure. The contrast range also improves.
Observing Endoplasmic Reticulum Present in Living Tissue Cultures through Phase Contrast Techniques
ER, or endoplasmic reticulum, is the organelle located inside the eukaryotic cells. These are interconnected in vesicles, tubules, and cisternae. These are all responsible for different special functions, especially those related to protein. Their composition and basic structure is more similar to a plasma membrane.
Initially, an electron microscope was used to first observe endoplasmic reticulum. With the different kinds of enhancements the electron microscopes have gone, there are also new documentations, showing the different occurrences of cytoplasmic membrane systems of animal cells. Since such reports only came from electron microscope analyses, the ER is in general considered to be a part that is of submicroscopic size.
Phase contrast images, however, have proven to be possible and, in fact, can provide almost the same kinds of results that are generated by electron microscopes. This is best illustrated by the experimented conducted by D. W. Fawcett and S. J Ito. They studied newly isolated testicular cells. The result has removed ER from the list of submicroscopic size.
Development of Zernike’s Theory
The development of the optical theory of phase contrast—as discovered by Zernike—is considered to be a very superb example of how research stemming from a very specialized field like that of theoretical physics can result to new innovative developments in unrelated disciplines like medicine and biology.
The first company who was able to integrate phase contrast optics to microscope was the one in Jena, Germany, called Zeiss Optical Works. This was during World War II. The impact it has on biological research was immediate and significant. Thus, there was widespread application of such technique until the present day. Today, contemporary phase contrast objectives can permit microscopes to operate in coordination with contrast-enhancing techniques like fluorescence, polarized light, and differential interference contrast.
The biological tissue observation using phase contrast microscope is set to further develop the field of medical and biological research for the years to come.
