Gram Staining Instructions
1a. If Sample is from
BROTH: Apply 1 or 2 loopfuls of broth to a
clean slide. DO NOT spread out drops. Air dry sample.
1b. If Sample is from
PLATE: Place a loopful of tap water onto a
slide. Touch a colony with a loop and mix the bacteria with the water until
there is a uniform, thin film of microorganisms on the slide. DO SPREAD
out the liquid as much as possible. Air dry sample
2. Heat fix the slide. Allow the slide to cool.
3. Stain with Crystal
Violet for 1 minute by
flooding the slide with stain. Rinse with water.
4. Apply Iodine solution
for 1 minute by flooding
the slide with iodine. Rinse with water.
decolorize for 3 seconds
with Gram Stain Decolorizer by flooding the slide with decolorizer.
IMMEDIATELY, rinse with water.
6. Counterstain with Safranin
for 30 seconds by flooding
the slide with stain. Rinse with water.
7. Dry the slide by putting it between the pages
of a book of Bibulous paper. Remove slide and view organisms using the
oil immersion objective of your microscope.
©1996,1997 Neal R. Chamberlain, Ph.D. and Betty
Cox, M.A.. All rights reserved.