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As per the exact chemistry, I am unsure, but basically the iodine acts to "set in" the stain by reacting the dye (crystal violet) from the previous step with the peptidoglycan layer, forming a layer which is now insoluble in the following step where the layer is washed with EtOH. If the cell is Gram (-), the iodine doesn't do much and the dye is washed away.
Iodine can be used as a mordant in dyeing to help the dye adhere to the fabric or yarn. It helps to fix the dye molecules onto the fibers, making the color more resistant to washing and fading. Iodine is particularly effective with natural fibers like wool and silk.
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Differences between lugols iodine and grams iodine?
Lugol's iodine is a solution of iodine and potassium iodide, used as a disinfectant and for staining purposes in microscopy. Gram's iodine is a complex of iodine, potassium iodide, and iodide, used in microbiology as a mordant for Gram staining. Gram's iodine is specifically used in the Gram staining technique to differentiate between bacteria based on their cell wall composition, while Lugol's iodine has broader applications in disinfection and staining.
What is the difference between iodine crystals and iodine solution?
Iodine crystals are solid, crystalline form of elemental iodine, while iodine solution is a liquid mixture of elemental iodine and either alcohol or water. Iodine crystals are typically used for storage and long-term preservation, while iodine solution is commonly used for disinfection and medical purposes.
What is the difference between povidone and tincture iodine?
Povidone-iodine is a stable chemical complex of polyvinylpyrrolidone and iodine, used as an antiseptic. Tincture iodine is a solution of iodine in alcohol, commonly used to disinfect skin before surgeries. Tincture iodine is more potent but can irritate the skin, while povidone-iodine is less irritating and commonly used in clinical settings.
What is the use of iodine flask?
An Iodine Flask is essential an Erlenmeyer Flask with a stopper used for the wet chemical analysis "Iodine Determination" . This analysis is typically performed on fatty acids, oils and shellac varnishes.
Why is KI used in estimation of iodine in tincture iodine?
Potassium iodide (KI) is used in the estimation of iodine in tincture iodine because it reacts with iodine to form a colorless complex, which can then be titrated with a solution of sodium thiosulfate to determine the amount of iodine present. The reaction is quantitative and allows for accurate quantification of iodine content in the tincture.
Why gram's iodine called a mordant?
Gram's iodine is called a mordant because it fixes the primary stain to the cell wall and adds any color.
Why is Iodine used in Gram staining?
Iodine is used in Gram staining as a mordant, which helps to bind the crystal violet dye to the cell wall of bacteria. This mordant-iodine complex forms larger complexes with the crystal violet dye, making it difficult for the dye to be washed away during the decolorization step. This allows for differentiation of Gram-positive and Gram-negative bacteria based on their ability to retain the crystal violet dye.
What is the mordant in a gram stain?
Gram's iodine stain is applied after the culture is stained with the primary stain. It acts as a mordant, fixing the primary stain to the cell wall while lending no additional colour to the cell (i.e. the mordant itself is not a stain). The mordant is only able to fix the stain to Gram-positive bacteria because of the characteristic thick, peptidoglycan coat that they possess. Because the mordant is not able to fix the stain to Gram-negative bacteria (who's coat have a different composition), the crystal violet stain will wash away from Gram-negative bacteria when the decolourizing agent is added.
What is the function of tincture iodine in trichrome stain?
Tincture iodine in trichrome stain is used as a mordant to enhance the staining of collagen fibers. It helps to improve the contrast and visibility of collagen in the tissue sample.
What is the mordant reagent for?
Mordant reagents are used in staining techniques to help bind dyes to specific structures. Different mordants are needed for different types of dyes and tissue components. For example, in Gram staining, the mordant reagent is iodine, which helps bind the crystal violet dye to the bacterial cell wall.
Is vinegar a mordant?
Yes, sodium chloride can be used as a mordant.
What is a dye which fixes without a mordant?
a mordant is used for the dyeing to try it
Why is gram's iodine called mordant?
Gram's iodine is called a mordant because it fixes the primary stain to the cell wall and adds any color.
Is iodine a basic stain?
No, iodine is not a basic stain. Iodine is commonly used in Gram staining to identify bacteria as either Gram-positive or Gram-negative based on their cell wall composition. It acts as a mordant in the staining process and helps to fix the crystal violet stain in Gram staining.
What mordant is used in spore staining?
Heat is the mordant used in the spore stain, it fixes the primary stain.
How do you use mordant in a sentence?
Alum was used as a mordant in dyeing. Salt is used as a mordant in dyeing and calico-printing. Mordant is very sarcastic and painful wit or speech. It is also known as a substance that attaches dyes to materials.
What is mordant used in the gram staining procedure and its function?
Iodine is the mordant used in the gram staining procedure. Its function is to complex with the crystal violet dye, forming large crystal iodide molecules that get trapped within the thick peptidoglycan layer of gram-positive bacteria. This helps to stabilize the crystal violet within the gram-positive bacteria, making them appear purple under the microscope.
