Pages

Wednesday, December 19, 2012

Gram Staining


In the past three weeks of my internship, I’ve learned more about biology by doing different experiments and doing some researches. Last week, which was the last week of fall semester, I was taught how to do Gram-staining. It was easy and super interesting for me. With this method (Gram Stain) you can categorizes bacteria based on the physical and chemical structure of their cell wall, also it distinguishes between Gram positive and Gram negative groups.



After making a slide of your sample, in my case was the bacteria that I growth before, Gram staining involves four processes: first add the crystal violet to the sample on the slide and leave it for 30 seconds, and then rinse it with distilled water. Then add the Gram iodine for 1 minute, and rinse the slide with water again. Next we need to use a Gram decolorize for almost 5 seconds and rinse it with water after 5 seconds. It decolorizes the sample if it’s a Gram negative and it will remove the crystal violet. For the last part, add the Safranin to the slide and after 30 seconds rinse the slide with distilled water for almost 5 seconds. If it’s a Gram positive bacteria, it keeps the crystal violet and it looks purple under microscope.

The slide that I got from Gram staining it shows on the picture below.


So when I viewed my slide under a microscope I got this picture, which it shows that it’s Gram positive and bacilli.



No comments:

Post a Comment