00:02
Let us understand the principle of differential staining which is denoted by df over here.
00:08
So differential staining may be involving components like stains represented by s over here, a mordant represented by m over here, and a decolorizer represented by d over here.
00:22
The stains might be of two kinds.
00:25
The primary stain represented as p over here and a secondary stain represented by s -e -c over here.
00:32
Here.
00:33
Now considering the case of gram staining, we know that in gram staining the cells either appear pinkish red in color or purple in color.
00:47
Let us understand the process of gram staining first.
00:50
So firstly a primary stain called crystal violet is used which is represented by c .b.
00:57
Over here.
00:58
This colors all the cells into purple color, irrespective.
01:02
Of their gram nature initially.
01:05
Then a mordant is used which helps to fix this color to the cells.
01:11
Then a decolorizer is used which helps in removal of this color.
01:18
Now this is possible in case of gram negative organisms only because they have less peptideoglycan and more lipids in their cell wall.
01:30
Thus the decolorizer here which is alcohol helps in removal of lipids.
01:36
Thus all the purple color from their initial staining is removed.
01:41
Now these gram negative cells are completely colorless...