Gram stain



Gram stain



Preparation and fixation of the sample :

1.    Smear the sample to be examined in a thin layer on a clear slide .

1.    Dry

1.    Fix with heat by rapidly passing the slide through a flame or with methanol cover the slide with alcehol and wait for 10 – 15 minutes unitill the alcahale has completely evaporated.

Staining

Cover the smear with crystal violet ( leave 1 minute ).

Rinse carfully water .

Cover with lugol ( 1 minute ) .

Rinse with water .

Decotorize with alchol acetone .

Cover with safranine ( 1 minute ) .

Rinse carfully water .

Dry

Reading:

Gram (+) appear purple .

Gram (-) appear pink