00:01
In order to answer this question, let's talk about gram staining.
00:04
It says, what is the purpose of each of the following chemical stains? so first, let's talk about each step of the gram staining.
00:11
So you're going to have here, gram positive, and here you're going to have gram negative.
00:15
So the step number one is going to be top -light crystal violet.
00:20
It's stated here, crystal violet.
00:27
This crystal violet is practically the primary stain, and it's going to be added to the specimen.
00:32
And in both cases, both bacteria, and positive and negative are going to stay in purple.
00:38
We're going to have here purple and also here purple.
00:42
The second step is to apply the iodine, and iodine is the more than, so particularly this more than is going to make the dye less soluble, so it is going to stick to the cell walls.
00:54
So your bacteria are going to remain also purple.
00:59
Then you have step number three, where you're going to apply alcohol, that is the colorizer, okay? this colorizer is going to wash away stain from gram negative cell walls.
01:11
It means they're going to make gram negative colorless, while gram positive are going to get my in purple.
01:19
Later, i'll tell you why.
01:21
And then step four is to apply suffering, that is the counter stain.
01:28
Okay, this counterstain is going to allow that adherence to gram negative cell wall, because as your grand negative cell wall, because as your grand negative, now is colorless then it can be stained again by another substance here okay so it is going to stain pink or red and your ground positive bacteria is going to the main purpose so it says what is the purpose of each of the following chemicals stains so crystal violet is the primary stain okay so this is the answer then you have grams iodine this iodine is going to be the mortal so it is going to help this crystal violet to stick to the cell walls of this bacteria and then you have this another that is the colorizer, it means it's going to help to remove the crystal violet from ground negative bacteria.
02:14
And finally, you have saffronin that is the counterstain that it is going to be able or it is going to help to stain again with a different color, a gram negative bacteria because they were colorless.
02:25
So you're going to be able to stain it again with another dye.
02:30
The next question is, what is a mortant? and a morton is practically a dye fixative.
02:37
It means it is going to help this crystal violet to be fixed to the cell walls of both gram positive and negative bacteria.
02:45
It says which of the chemicals from the list above acts as a mordant and it is going to be iodine.
02:50
Then you have what is a counterstain...