Gram staining method

In this post i am going to describe gram staining method in brief.

Introduction

Gram staining procedure is a differential staining method used to differentiate between gram positive and gram negative bacteria.
First used by Hans Christian Gram.
Gram positive bacteria stains violet or dark blue.
Gram negative bacteria stains red.

Materials

Crystal violet; used as a primary stain

Safranin; used as a counter stain

Grams iodine

Glass slide

Distilled water

Decolorizer (ehtanol)

Inoculating loop

Procedure
1. Take the slide and wash it,dry it.

2. Take a drop on the slide.

3. Using inoculating loop take the bacterial sample and mix it in the water drop.

4. Make a smear of the water drop.

5. Air dry the smear.

6. Heat fix the smear.

7. Add crystal violet on the smear for 45sec to 1min.

8. Then add grams iodine(you can also wash the crystal violet with distilled water before adding iodine) and wait for 30 sec to 45 sec.

9.wash with decolorizer.

10. Add safranin. Wait for 45 sec to 1 min.

11. wash with distilled water.

12.dry, and observe under microscope.

Observation and result
If you observe purple or dark blue color cells, then the cells are gram positive; on the other hand if you see cells with colour red then the cells are gram negative.


Hope this post will help you. 
                                           (~Bio blog)

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