Knowing More About Dyeing and Examining the Different Parts of the Cell in Phase Contrast Microscopy

The phase contrast microscope is a specialty microscope that is especially used in viewing and examining biological tissues. That would include the in-depth study of different cell parts for medical use and research. Light microscopy using this microscope gives a different enhancement of the contrasting colors in transparent or colorless specimens by controlling the optical light path. Without this feature, viewing minute cell parts is almost impossible.

The change in the phase because of slower light travel can be hastened by a phase contrast microscope so that there will be a positive change in the brightness. This way, the object being viewed shines as compared to the rest of the background.

In fluorescence microscopy, dyes are used to bring out differing colors in cell parts so there is a distinct separation between the parts of the cell. What happens here is that irradiation excite the molecules of the dye substance causing a red shift of the wavelength to a greater magnitude so that dyes now become visible in viewing specimens parts. When used biomedically, cell regions are given labels simultaneously by the different dyes incorporated into the cell so that there is more visibility of the parts thereby allowing closer examination of all parts.

So how is staining or dyeing done? Staining is a technique used to dye a substrate to give quality or quantity to the compounds contained within the cell parts. This is a way to highlight different structures in the tissues for better viewing. This means that the different chemical compounds found in the different parts react to the dye so that the reaction is shown as a change in its color. The quality of the compound and the quantity of such can be determined.

When is this technique used? In the fields of biology and also medicine, this technique plays a very important role. The use of a microscope is necessary to make viewing of the image possible. Tissues that are usually dyed or stained are bulk tissues like muscle fibers, connective tissues, cell populations like blood cells or even the organelles found in every living cell.

The staining done will be used to mark the different cells if there is the presence of proteins or nucleic acids.

This technique may also be done in vitro where the coloring or dyeing are done to cells that are no longer living. Sometimes, a combination of different dyes may be done to give a revelation of more vivid details and features than using a single dye. After the dyeing technique, certain techniques in fixating the specimen to give it permanency are done. After which, mounting is also necessary so that the specimen will be rendered useful for future use.

Tricks may be incorporated if the primary stain done has not been effective in bringing out the details. A counterstain may be used to provide contrast. This is best exemplified in gram staining where the substance crystal violet will one stain gram-positive bacteria while safranin will be infused to stain all parts. This is to give contrast to the cells that have been dyed by the crystal violet allowing the viewer to see the bacteria clearly.

The exact steps in staining the sample are done by immersing the whole thing before it is fixated and mounted in the dye solution. After that, rinsing is necessary to remove excess dye. Sometimes, a mordant (chemical compound that reacts to the stain) is used so that during rinsing, the mordanted stain will stay with the parts dyed.

There are many uses for this in the medical field. The Papanicolaou staining is widely used for Pap-smears to see if there is cervical cancer in women. The periodic acid-Schiff staining techniques mark the presence of glycogen storage diseases. The Romanowsky stain is used to examine blood or even bone marrow specimens to determine if there is the presence of leukemia in patients or if there is malaria in the blood.

Other staining techniques like silver staining are done to reveal proteins and DNA for important determination of genetic diseases. Sudan staining, on the other hand, can determine the presence of lipids especially fats in the feces to see if there steatorrhea.

Because of the high relevance of the use of dyeing in the examination of cell parts, advances in medical technology have been made possible. The early diagnosis of diseases can now be done using this technique together with skilled microscopy. Many new diseases and strains of viruses and bacteria have been discovered also because of this technique.

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