Gram Staining
Material
- Microscope slide with heat fixed sample.
- Set of dyes. Methyl-Violet and Safranin.
- Alcohol-Acetone decolorizer.
- Metal tweezers.
- Stopwatch.
Procedure
1.Immerse the microscope slide in methyl violet for 1 minute.
2.Wash with water and leave it to drain.
3.Immerse it in lugol’s iodine. Leave it for 1 minute.
4.Wash with water and leave it to drain.
5.Discolor it with alcohol-acetone for 15 seconds.
6.Take it out and immediately immerse it in safranin to compare it. Leave it in for 1 minute.
7.Wash with water and dry it with filter paper.
In the microscopic observation the Gram-positive bacteria have been dyed purple and the Gram-negative bacteria are pink.