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In Gram staining procedure during bacterial staining , iodine forms a complex with crystal violet stain which stains Gram positive bacteria blue to violet .
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Functions of iodine?
Iodine act as modrant for crystal violet and helps its attachement more firmly.
Function of iodine in Gram stain?
iodine act as a mordant..on the gram positive bacteria which got really thick and abundence of peptidoglycan layer, the crystal violet will fix to the peptidoglycan layer..meanwhile in gram negative bacteria which is lack of peptidoglycan layer, the alcohol or acetone will wash it away
Why is iodine called iodine?
It is called iodine because the Greek word for violet is iodes
Its crystals sublime as violet gas iodine or bromine?
Iodine c:
What is the difference between iodine crystals and iodine solution?
Iodine crystal is solid Iodine. Iodine solution is when Iodine crystals are dissolved in water.
Why is Iodine used in Gram staining?
Iodine is added as a mordant to enhance crystal violet staining by forming a crystal violet-iodine complex.
What is the secondary stain in gram stain procedure?
It is crystal violet & stains all cells purple.
What happens if grams iodine is not applied after staining with crystal violet?
If the iodine in the Gram's stain was omitted, the crystal violet which enters the cell will not be able to form the Crystal Violet Iodine (CVI) complex. The CVI complex molecule has a larger size than that of Crystal violet molecule and hence Gram +ve bacteria are able to retain the stain. If iodine were omitted, even Gram+ve cells would get decolorised by Alcohol treatment and would be seen as Gram-ve cells.
Function of Gram's iodine?
Iodine is used as a mordant in the gram staining procedure to make large crystals when it is used with crystal violet dye. In gram positive cell walls those crystals get stuck and wont get washed off with the alcohol. In gram negative cell walls the crystals are washed out.
Functions of iodine?
Iodine act as modrant for crystal violet and helps its attachement more firmly.
What is the action of iodine in grams stain?
Iodine is used to bind the Crystal Violet to the Gram Positive microbes.
If iodine step was amitted how would gram negative cells appear?
Iodine work as modrant to crystal violet if the iodine step will be emitted then the crystal violet will not be able to show its effect and all cells will appear pink when counter stain with saffranin
Does the age of the culture affect the gram stain?
Yes, the age of the culture may influence the results of the stain. With the current theory behind gram staining, it is thought that in gram-positive bacteria, the crystal violet and iodine combine to form a larger molecule that precipitates out within the cell. The alcohol/acetone mixture then causes dehydration of the multilayered peptidoglycan in the gram-positive call wall, thus decreasing the space between the molecules and causing the cell wall to trap the crystal violet-iodine complex within the cell. In the case of gram-negative bacteria, the alcohol/acetone mixture, being a lipid solvent, dissolves the outer membrane of the gram-negative cell wall (and may also damage the cytoplasmic membrane to which the peptidoglycan is attached). The thin layer of peptidoglycan is unable to retain the crystal violet-iodine complex and the cell is decolorized. It is important to note that gram-positivity (the ability to retain the purple crystal violet-iodine complex) is not an all-or-nothing phenomenon but a matter of degree. There are several factors that could result in a gram-positive organism staining gram-negatively: 1. The method and techniques used. Overheating during heat fixation, over decolorization with alcohol, and even too much washing with water between steps may result in gram-positive bacteria losing the crystal violet-iodine complex. 2. The age of the culture. Cultures more than 24 hours old may lose their ability to retain the crystal violet-iodine complex. 3. The organism itself. Some gram-positive bacteria are more able to retain the crystal violet-iodine complex than others.
Does the age of the culture affect the gram staining reaction?
Yes, the age of the culture may influence the results of the stain. With the current theory behind gram staining, it is thought that in gram-positive bacteria, the crystal violet and iodine combine to form a larger molecule that precipitates out within the cell. The alcohol/acetone mixture then causes dehydration of the multilayered peptidoglycan in the gram-positive call wall, thus decreasing the space between the molecules and causing the cell wall to trap the crystal violet-iodine complex within the cell. In the case of gram-negative bacteria, the alcohol/acetone mixture, being a lipid solvent, dissolves the outer membrane of the gram-negative cell wall (and may also damage the cytoplasmic membrane to which the peptidoglycan is attached). The thin layer of peptidoglycan is unable to retain the crystal violet-iodine complex and the cell is decolorized. It is important to note that gram-positivity (the ability to retain the purple crystal violet-iodine complex) is not an all-or-nothing phenomenon but a matter of degree. There are several factors that could result in a gram-positive organism staining gram-negatively: 1. The method and techniques used. Overheating during heat fixation, over decolorization with alcohol, and even too much washing with water between steps may result in gram-positive bacteria losing the crystal violet-iodine complex. 2. The age of the culture. Cultures more than 24 hours old may lose their ability to retain the crystal violet-iodine complex. 3. The organism itself. Some gram-positive bacteria are more able to retain the crystal violet-iodine complex than others.
Function of iodine in Gram stain?
iodine act as a mordant..on the gram positive bacteria which got really thick and abundence of peptidoglycan layer, the crystal violet will fix to the peptidoglycan layer..meanwhile in gram negative bacteria which is lack of peptidoglycan layer, the alcohol or acetone will wash it away
Function of crystal violet?
Crystal violet is a hexamethyl also known as methyl violet 10B This is much darker than 2B, and often darker than 6B. It is used in biological stainang particularly gram staining together with safranin and iodine. Crystal violet was also used to treat strept throat. Doctors used to swab it on the back of your throat.
What is the purpose of mordant in a differential staining procedure?
The resultant crystal violet- iodine (CV-1) complex serves to intensify the-color of the stain. At this point, all cells will appear purple black.
