Gram Stain and Acid Fast Staining of Microorganism

¶ … Microorganisms Through a Microscope

The Gram stain test distinguishes two fundamental cell varieties of bacteria. The latter also determines the presence of bacteria. "Gram-positive" refers to the type that retains the original crystal violet stain. In contrast, the decolorized stain red depicts the "gram-negative" variety. The significance of the staining plays a crucial role in the determination of the appropriate treatment for an infection. Often, the clarity in distinguishing between viral, fungal, and bacterial infections may not be attained (Wojewoda et al. 2073). This requires the application of the gram stain test. Additionally, various bacterial varieties may necessitate the use of different treatments. The use of gram stain technique enables physicians to establish that the infection is because of bacteria. The test also provides fast results that are beneficial for the diagnosis process.

The acid-fast stain can be used to identify microbes in the genera Mycobacterium and Nocardia. A majority of the bacteria emerging from the genera Mycobacterium and Nocardia result in infectious ailments that include tuberculosis and skin infections. The test facilitates the identification of the various segments of bacteria. The technique engages two approaches. The Ziehl-Neelsen approach involves the use of heat whereas the Kinyoun technique employs a detergent that reduces the surface tension of fats. The bacteria within the Mycobacterium and Nocardia genera possess unusual cells walls characterized by wax and close to impermeability. The presence of mycolic acid molecule explains the latter. The resistance of the cell wall to water-based stains demands the application of heat to propel stain into the cell wall. The steps to this acid-fast stain technique are Carbol Fuchsin (10-15 minutes), Acid Alcohol (3-5seconds), Methylene Blue (2 minutes), and blotting slide dry gently with the use of a bibulous paper.

The negative stain does not colorize because its chromogen that carries the negative charge faces repulsion on the cell's bacterial surface due to the presence of a negative charge (Jiang and Doudna 103). Consequently, the bacterial cells remain unstained. However, they remain distinguishable against the colored background. During a cell wall stain, the whole cell does not stain because the employed dyes get attracted to the negative cell. However, the inside of the cell remains clear. As a result, the negative stain can be referred to as the indirect stain. The technique facilitates the visualization of cells deemed too delicate to undergo heat fixing. The method allows the preservation of the sample without distortion because no heat is used. As a result, the determination of the size and arrangement of bacteria comes out more accurately.

Transmission Electron Microscope (TEM) engages energetic electrons to deliver sample information based on various aspects of composition, crystallization, and morphology (Reimer 46). TEMs dispense two-dimensional images that are of high-resolution. The microscopes play a crucial role in contemporary material science with the investigation of the ceramics, minerals, and chemistry of metals. Transmission electron microscopy facilitates physical manipulation of samples, for example, compression to measure mechanical properties. TEMs allow the generation of characteristic X-rays from samples to facilitate microanalysis. The applications of TEMs spread from industry, education, and science.