Explain Procedure for Gram Staining of Bacterial Cultures?
Now carry out the exercise following the steps enumerated herewith.
1. Prepare bacterial smear on a clean, non-greasy slide from the given culture(s). For this, a drop of water is placed on the slide, culture is transferred, mixed and spreaded by the circular motion of the sterile inoculating loop. Similarly, prepare a bacterial smear consisting of a mixture of organisms on one slide.
2. Now allow the bacterial smear to air dry and then heat fixed.
3. Put the slide on staining tray and flood the smear with crystal violet for one minute.
4. Rinse the slide gently under tap water.
5. Flood the smear with gram's iodine for one minute.
6. Wash gently with tap water.
7. Decolourize the slide with 95% ethanol or acetone by adding it drop-wise till the colour comes out.
8. Wash immediately with tap water.
9. Counter stain with safranin for 30-60 seconds. 10. Again wash gently with tap water.
11. Blot dry and examine in the microscope under oil immersion. A summary of the procedure and the process is highlighted herewith.