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What will be the color of the gram positive if iodine step left out?
Wiki User
∙ 13y ago
Since you've missed the iodine step and you're going to put a decolorizer(alcohol) into it for the next step , naturally it will lost it's color. Because iodine acts as a mordant, which means it helps the gram positive to retain it's color.
Wiki User
∙ 13y ago
Wiki User
∙ 10y agoIodone works with the gram stain to fix the color of the dye. Without it, it would be more difficult to notice the color which would in turn cause the color to essentially decolorize causing everything to look red.
Wiki User
∙ 16y agoIf the decolorizer step is omitted, all bacteria will appear Gram positive.
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If iodine step missed in gram stain what will happen?
Iodine (I - or I3 - ) interacts with CV+ and forms large complexes of crystal violet and iodine (CV-I) within the inner and outer layers of the cell. Iodine is often referred to as a mordant, but is a trapping agent that prevents the removal of the CV-I complex and, therefore, color the cell.[10]
Why do gram negative cells stain pink?
Gram negative bacteria actually stain red because they have a less complex cell wall than Gram positive bacteria and they are easily decolorised by the decoloriser acetone alcohol. Hence they take up the colour of the counter stain safranin which is red during the Gram staining procedure.
What is the purpose of control test in gram stain?
Gram staining is a simple staining test that simply identifies the two main groups of bacteria. Gram positive, and gram negative. Down a microscope, gram pos look like a dark blue/purple colour, and gram neg look red. It is to do with what the wall of the bacteria comprises of, and without going into too much detail, certain drugs work on gram pos bacteria, and others wont. Likewise for gram neg.
Which step is most crucial or most likely to cause poor results in the gram stain?
Gram staining is a type of differential staining in which two types of bacteria are differentiated on the basis of their cell wall either gram positive or gram negative although all the steps in gram staining are crucial, the most important step the most crucial step in the performance of the Gram staining procedure is the decolorization step which is the Acid-Alcohol (3% HCl and 95% Ethanol) and must be timed correctly; the crystal violet stain will be removed from both Gram-positive and negative cells if the decolorizing agent is left on too long (a matter of seconds).
Why does alcohol decolorize gram negative bacteria?
Gram Negatice bacteria contain a cell membrane made up of thinner peptidoglycan layer plus a lipopolysaccharide layer, unlike gram positves bacteria's thick peptidoglycan layer. Alcohol delcolourizes gram negative bacteria because it disrupts the lipopolysaccharide and the crystal violet-iodine complex is able to now pass through the thin layer of peptidoglycan left leaving no crystal violet colour in the gram negatice bacteria that can now take up the red/pink colour of the safranin introduced be the subsequent counterstaining procedure.
What is a gram variable bacteria?
gram-positive bacteria but can become gram negative if the smear is left to culture for a long period of time.
If iodine step missed in gram stain what will happen?
Iodine (I - or I3 - ) interacts with CV+ and forms large complexes of crystal violet and iodine (CV-I) within the inner and outer layers of the cell. Iodine is often referred to as a mordant, but is a trapping agent that prevents the removal of the CV-I complex and, therefore, color the cell.[10]
Radioactive iodine-131 has a half-life of eight days. The amount of a 200.0 gram sample left after 32 days would be -?
12.5 g
What are the three basic Theories on the principle of gram staining reactions?
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 crystalls and apear purple. Gram negative cells only have a thin peptidoglycan layer that allows the crystals to diffuse out of the cell and will only be seen with the application of a counterstain, such as safranin which turns the cells pink.
Why do gram negative cells stain pink?
Gram negative bacteria actually stain red because they have a less complex cell wall than Gram positive bacteria and they are easily decolorised by the decoloriser acetone alcohol. Hence they take up the colour of the counter stain safranin which is red during the Gram staining procedure.
In a gram stain if alcohol is left out what color would a Gram-negative bacterium turn out?
If you stop at this stage (without the alcohol), the Gram-negative cells will be invisible since they have lost their crystal violet stain.
Why is the difference color between gram positive and gram negative bacteria?
It is because of the thickness of the peptidoglycan cell wall of the bacteria. Gram positive bacteria have a larger/thicker cell wall. It is this cell wall which retains the stain of the crystal violet(primary stain) and carbol fuschin(counterstain). Gram negative have a very thin cell wall. So when the Acetone solution is applied in between stains the crystal violet is washed out of the gram negative bacteria. As it is only left on for a few seconds the gram positive bacteria can still retain the crystal violet solution due to the cell wall thickness. The counterstain is then added. because the gram negative bacteria have been 'unstained' by the acetone the fuschin (pink stain) is absorbed and therefore shown when looked at under a microscope.
How do you separate iodine and alcohol?
You can boil away the alcohol, and the iodine will be left behind as a solid residue.
How long would it take for iodine-131 to decay into xenon?
The half life of Iodine-131 is 8.02 days, that means that say if you had 1 gram of 131I after approximately 8 days there would be only 0.5g left. The other half would have become Xenon-131. After 6 half lives (~48 days in your case) you would only have 1.6% of the original amount left.
What is the purpose of control test in gram stain?
Gram staining is a simple staining test that simply identifies the two main groups of bacteria. Gram positive, and gram negative. Down a microscope, gram pos look like a dark blue/purple colour, and gram neg look red. It is to do with what the wall of the bacteria comprises of, and without going into too much detail, certain drugs work on gram pos bacteria, and others wont. Likewise for gram neg.
How do you separate iodine and methyl alcohol?
You can boil away the alcohol, and the iodine will be left behind as a solid residue.
Which step is most crucial or most likely to cause poor results in the gram stain?
Gram staining is a type of differential staining in which two types of bacteria are differentiated on the basis of their cell wall either gram positive or gram negative although all the steps in gram staining are crucial, the most important step the most crucial step in the performance of the Gram staining procedure is the decolorization step which is the Acid-Alcohol (3% HCl and 95% Ethanol) and must be timed correctly; the crystal violet stain will be removed from both Gram-positive and negative cells if the decolorizing agent is left on too long (a matter of seconds).
