What Is Responsible For The Differences In The Gram Stain Reactions Of The Above Microorganisms?

Due to differences in the thickness of a peptidoglycan layer in the cell membrane between Gram positive and Gram negative bacteria, Gram positive bacteria (with a thicker peptidoglycan layer) retain crystal violet stain during the decolorization process, while Gram negative bacteria lose the crystal violet stain and

What is responsible for the differences in the Gram stain reactions of the 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 factors can affect the Gram stain reaction?

The many variables that can affect this stain are age of the culture, amount of decolorizer used, the time of decolorization, the type of organism (acid-fast bacteria and spores do not stain well), thickness of the smear, and the general care of the stainer.

Why do certain bacteria stain differently when stained with Gram stain?

Gram-positive and Gram-negative bacteria stain differently because of fundamental differences in the structure of their cell walls. The bacterial cell wall serves to give the organism its size and shape as well as to prevent osmotic lysis. The material in the bacterial cell wall which confers rigidity is peptidoglycan.

How does the Gram stain work to differentiate 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.They are stained pink or red by the counterstain, commonly safranin or fuchsine.

What is the principle behind the Gram stain reaction explain briefly?

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 are the Gram staining procedure?

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 factors are responsible for Gram variability?

Variations in Gram Reaction

• Cell wall damage of bacteria due to antibiotic therapy or excessive heat fixation of the smear.
• Over- decolorization of the smear.
• Use of an Iodine solution which is too old, i.e. yellow instead of brown in color (always store in a brown glass or other light opaque containers).

What causes Gram stain variability?

The exposure of heat-fixed bacterial smears to relative humidities of 0, 52 and 98%, following the iodine step in a dry Gram stain procedure, markedly influenced the rate of decolorization upon exposure to 95% ethyl alcohol.

What is the difference between simple staining and Gram staining?

Answer: gram staining is a differential staining techniques that uses a primary stain and a secondary counterstain. simple staining can be used as a quick and easy way to determine cell shape size and arrangements of bacteria.

Why do certain bacteria stain differently when stained with Gram stain quizlet?

Why do bacteria respond to a Gram stain differently? Because of the differences in the structure of their cell wall. Because of the thickness of peptidoglycan in their cell walls. Those with thick peptidoglycan in their wall are stained purple and are known as Gram positive.

What cell structure causes some bacteria to stain Gram positive while others stain gram negative?

The staining procedure differentiates organisms of the domain Bacteria according to cell wall structure. Gram-positive cells have a thick peptidoglycan layer and stain blue to purple. Gram-negative cells have a thin peptidoglycan layer and stain red to pink.

What is Gram staining in microbiology?

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.

Which of the following correctly describes how the Gram stain works to color different types of cells?

which of the following correctly describe how the Gram stain works to color different types of cells? gram-positive cells retain the purple dye-mordant complex because of their thick layer of peptidoglycan.

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 the Gram staining technique quizlet?

What is the purpose of Gram Stain? To be able to determine the composition of the cell wall. The advantage of this staining procedure is that those cells that decolorize can be differetiated from the cells that resist decolorization by alcohol.

What is the principle of the Gram stain process quizlet?

Principle: Gram stain is differential stain which a decolorization step occurs between the application of 2 basic stains.

What is the aim of Gram staining experiment?

Purpose: is to determine the Gram stain of your bacterial sample. Introduction: Gram staining is a method commonly used to determine the chemical make up of the cell wall of bacteria. The cell wall can stain either positive or negative, depending on its chemistry.

What are the two major purpose of the process of Gram staining?

What is Gram Staining? Gram staining is a common technique used to differentiate two large groups of bacteria based on their different cell wall constituents. The Gram stain procedure distinguishes between Gram positive and Gram negative groups by coloring these cells red or violet.

How do you perform a Gram stain in microbiology?

DIRECTIONS

1. Apply a smear of bacteria on to a slide.
2. Add about 5 drops of Hucker’s Crystal Violet to the culture.
3. Add about 5 drops of iodine solution to the culture.
4. Tilt slide and decolorize with solvent (acetone-alcohol solution) until purple color stops running.
5. Add about 5 drops of Safranine O.

What is the most important reagent in the Gram stain method?

The primary stain of the Gram’s method is crystal violet. Crystal violet is sometimes substituted with methylene blue, which is equally effective. The microorganisms that retain the crystal violet-iodine complex appear purple brown under microscopic examination.