The basic principle of gram staining involves the ability of the bacterial cell wall to retain the crystal violet dye during solvent treatment. Gram-positive microorganisms have higher peptidoglycan content, whereas gram-negative organisms have higher lipid content.
What is the principle behind the Gram stain reaction explain briefly quizlet?
What is the current theory about the mechanism of the gram stain reaction? The gram stain is a basic differential stain used to determine if a bacterial cell is gram positive or negative. Gram positive cells have a thick peptidoglycan layer that will trap the crystal violet iodine crystals and appear purple.
What is the principle of Gram staining How does it differentiates between bacteria?
Gram staining differentiates bacteria by the chemical and physical properties of their cell walls. Gram-positive cells have a thick layer of peptidoglycan in the cell wall that retains the primary stain, crystal violet.
What is the principle behind the simple staining?
Simple staining involves directly staining the bacterial cell with a positively charged dye in order to see bacterial detail, in contrast to negative staining where the bacteria remain unstained against a dark background.
What is differential staining describe the principle and procedure of Gram staining?
Gram staining is a differential bacterial staining technique used to differentiate bacteria into Gram Positive and Gram Negative types according to their cell wall composition. It is the most widely used and the most important staining technique in bacteriology, especially in medical bacteriology.
What is the clinical significance of the Gram stain quizlet?
The gram stain is useful in a clinical lab because it distinguishes between gram positive and gram negative cells, which aid in identifying a species or narrowing down the possibilities. It allows us to determine the cell arrangement, size, and morphology.
What type of stain is a Gram stain quizlet?
Terms in this set (14) What is a gram stain? It’s a DIFFERENTIAL stain that allows for classification of a bacteria as either gram-positive or gram-negative. Discovered by Hans Christian Gram.
What is the principle of acid fast bacilli?
PURPOSE: Used in the demonstration of acid-fast bacteria belonging to the genus ‘mycobacterium’, which include the causative agent for tuberculosis. PRINCIPLE: The lipoid capsule of the acid-fast organism takes up carbol- fuchsin and resists decolorization with a dilute acid rinse.
What type of stain is the Gram stain and what does it rely on for meaningful results?
Some labels will NOT be used. What type of stain is the Gram stain, and what does it rely on for meaningful results? A. It is a simple stain that relies on chemical differences in the plasma membrane to yield meaningful results.
What is the purpose of a Gram stain?
A Gram stain is a test that checks for bacteria at the site of a suspected infection such as the throat, lungs, genitals, or in skin wounds. Gram stains may also be used to check for bacteria in certain body fluids, such as blood or urine.
What are the steps in Gram staining?
The performance of the Gram Stain on any sample requires four basic steps that include applying a primary stain (crystal violet) to a heat-fixed smear, followed by the addition of a mordant (Gram’s Iodine), rapid decolorization with alcohol, acetone, or a mixture of alcohol and acetone and lastly, counterstaining with
What is basic stain in microbiology?
Basic stains, such as methylene blue, Gram safranin, or Gram crystal violet are useful for staining most bacteria. These stains will readily give up a hydroxide ion or accept a hydrogen ion, which leaves the stain positively charged.
What is the importance of staining in microbiology?
The most basic reason that cells are stained is to enhance visualization of the cell or certain cellular components under a microscope. Cells may also be stained to highlight metabolic processes or to differentiate between live and dead cells in a sample.
What is Gram staining What are the reagents and procedure in Gram staining?
Reagents needed for Gram staining include:
Crystal violet (primary stain) [1] Gram’s iodine solution (the mordant) [1] Acetone/ethanol (50:50 v:v) (the decolorizer) [1] 0.1% basic fuchsin solution (the counterstain) [1]
What is responsible for the differences in the Gram stain reactions of the above microorganisms?
The differences in cell wall composition of Gram-positive and Gram-negative bacteria account for the Gram staining differences. Gram-positive cell wall contains a thick layer of peptidoglycan with numerous teichoic acid cross-linking which resists the decolorization.
What are the functions of the individual stains and reagents used in Gram staining?
The first reagent is called the primary stain. Its function is to impart its color to all cells. The second stain is a mordant used to in- tensify the color of the primary stain. In order to es- tablish a color contrast, the third reagent used is the decolorizing agent.
Why do we use positive and negative controls in the Gram stain?
The positive and negative controls are bacterial smears we use to test if the Gram stain was performed properly. If the positive and negative controls are not as expected, you can not trust that the stain was performed properly. As a Positive Control we use a known Gram-positive bacteria.
What are the two functions of bacterial appendages?
The two functions of bacterial appendages are attachment and motility. Attachment is the bacteria’s ability to stick to the surface of something. Pili…
What characteristics can be determined in a Gram stain quizlet?
What two cell characteristics can be determined by using the Gram stain? Cell shape and cell wall structure can be determined from a Gram stain.
What stains are used in Gram staining?
Reagents Used in Gram Staining
- Crystal Violet, the primary stain.
- Iodine, the mordant.
- A decolorizer made of acetone and alcohol (95%)
- Safranin, the counterstain.
What are the steps of the Gram staining procedure quizlet?
Terms in this set (11)
- Place a slide with a fixed smear on a rack over a staining tray or a sink.
- Cover the smear with crystal violet for 20 seconds.
- Rinse the slide with water to remove excess crystal violet.
- Cover the smear with Gram’s iodine for 1 minute.
- Rinse the slide with water to remove excess iodine solution.
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