Gram staining: principle,requirment and procedure.short notes ~ Statusdeewane

Gram staining:- identification of gram positive and gram negative bacteria

PRINCIPLE:-
gram positive cell wall contain thick layer of peptidoglycan.
Gram negative bacteria contains thin layer of lipopolysaccharide.

Used crystal violet to stain cell walls,gram iodine used to mordant and fixations.
Acetone are used to decolourizer and safranin used to mark of all bacteria.

REQUIREMENTS:-
•slide
•sample
•crystal violet
•gram iodine
•decolourizer (acetone/alcohol)
•safranin
•microscope

PROCEDURE:-
▪︎preparations of smear oval shaped.
▪︎air dry
▪︎add crystal violet for 1 minute
▪︎wash the slide
▪︎add gram iodine for 1 minute
▪︎wash the slide
▪︎add acetone or alcohol for decolourizer 8 to 10 seconds
▪︎wash the slide
▪︎add safranin for 30 seconds to 1 minute
▪︎wash the slide
▪︎air dry and observe under the microscope 100x oil immersion lens.

OBSERVATIONS:-
gram posive bacteria---purple coloured
Gram negative bacteria--red and pinkish colored.