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Gram Lab
Gram Staining Lab
The Gram staining of bacteria is one of the most important tests in identifying specific bacterial strains, and is usually the first test performed when medical or research laboratories need to identify an unknown bacteria (Xu, 1997; AACC, 2011). Named for the inventor of the technique, Hans Christian Gram, Gram staining first came into use in Gram's own Danish medical and research practice in 1882, and became very widely known and used after the details of the technique were published in 1884 (Xu, 1997). Though some adjustments can be made to the original technique without losing effectiveness, the basic process of Gram staining has remained unchanged for over a century, and is as effective and essential a test today as it was in the latter half of the nineteenth century (Xu, 1997).
Simply put, the Gram staining test often (though not always) allows the researcher to determine the broad class of bacteria that an unknown species belongs to by using dyes and washes that are absorbed and retained differently by different bacteria (AACC, 2011). Crystal violet dye is the standard dye used in the first step of Gram stain...
Those bacteria that retain the dye and thus take on a crystal violet hue are called Gram positive, while those bacteria that do not retain the dye (and are usually stained with another dye to provide better contrast in subsequent steps of the test are Gram negative (AACC, 2011; Xu, 1997).
Steps in Gram Testing
The first step of Gram stain testing, after properly preparing a slide with a smear of bacterial culture, is to add crystal violet stain to the slide containing the culture smear in order to allow Gram positive bacteria to absorb the dye (Xu, 1997). The dye only needs to set for ten seconds to up to a minute, though it can be even more immediate for very thinly prepared slides (Xu, 1997). After the staining, washing away the excess dye with a thin and gentle stream of water (taking care not to wash off the sample itself) is necessary, and the sample is then saturated in an iodine solution and rinsed again, this time in order to bring out the…
References
AACC. (2011). Gram Stain. American Association for Clinical Chemistry. Accessed 14 September 2011. http://labtestsonline.org/understanding/analytes/gram-stain/tab/test
Xu, G. (1997). Gram stain. University of Pennsylvania Health System. Accessed 14 September 2011. http://www.uphs.upenn.edu/bugdrug/antibiotic_manual/gram.htm
Gram Stain Bacteria Identification Following standard procedure for Gram staining, a slide was prepared by heat fixing the sample and applying the primary crystal violet stain (Bruckner, 2012). After incubation in the primary stain for a period of one minute, the stain was rinsed under a slow stream of water for four seconds before fixing the remaining dye with Gram's iodine, with immersion in this mordant lasting one minute (Bruckner, 2012). Following
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
Treatment to Patients The main objective of providing treatment to patients is to relieve symptoms along with decreasing the progression of the disease as well as the mortality or morbidity. However, in some cases, this objective is not fully achieved, especially in the case of the patients who are admitted to the ICU with some serious and almost always a terminal stage of the disease. For example, when old patients