slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Principle of staining technique: PowerPoint Presentation
Download Presentation
Principle of staining technique:

Loading in 2 Seconds...

play fullscreen
1 / 16

Principle of staining technique: - PowerPoint PPT Presentation


  • 1995 Views
  • Uploaded on

Gram Stain. Principle of staining technique:. Primary stain:- Crystal Violet Mordant(fixes the dye):- Iodine Decolorizing agent:- Alcohol/Acetone Counter stain;- Safranin. Why do gram-positive cells keep their color while gram- negative cells lose it?.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

Principle of staining technique:


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Gram Stain

Principle of staining technique:

  • Primary stain:- Crystal Violet
  • Mordant(fixes the dye):- Iodine
  • Decolorizing agent:-Alcohol/Acetone
  • Counter stain;- Safranin
slide2

Why do gram-positive cells keep their color while gram- negative cells lose it?

Due to the difference in the structure of the cell wall.

Gram-negative cells have peptidoglycan (less)+ NO teichoic acid+ large amount of lipids

Alcohol dissolves the lipids , forms large pores that leak the dye leading to loss of CV/Iodine complex.

Gram-positive cells have peptidoglycan + teichoic, no pores are formed by alcohol and the dye is retained.

+ve: Retention of the crystal violet/

Iodine complex

-ve: Loss of the crystal violet/ Iodine complex

slide3

Gram stain

Gram +ve

Gram –ve

slide4

Gram stain

Procedure:

  • 1.Shake the suspension very well.
  • 2.Transfere Aseptically 3-4 loopfuls to
  • a clean glass slide marked from below.
  • 3.Air or heat drying
  • 4.Heat fixation
  • 5.Cover film with CV leave for(30 sec)
slide5

Gram stain

Procedure:

6. Wash gently

7. Cover the film with Iodine leave for(2 min),discard

8.Add fresh Iodine leave for (1min)

slide6

Gram stain

Procedure:

9. Wash gently

10. Decolorize by covering the film using Alcohol /Acetone for 5 sec .

slide7

Gram stain

Procedure:

11. Wash gently

12. Cover film with Safranin

leave for (5 min)

slide8

Gram stain

Procedure:

13. Wash gently

14. Leave to dry

15. Add Oil

16. Use Oil Immersion lens

3 streak the agar cont
3. Streak the agar (cont.)
  • Gram stain

Precautions

Avoid excessivedecolorization

Avoid insufficientdecolorization

Stains are added on cool slides

Don’t dry by heat after staining