Endospore Stain Procedure:


1.  Prepare smears of organisms to be tested for endospores.

2.  Heat fix the smears.

3.  Cover the smears with a piece of absorbent paper cut to fit the slide and place the slide on a wire gauze on a ring stand.
4.  Saturate the paper with malachite green and holding the Bunsen burner in the hand heat the slide until steam can be seen rising from the surface.  Remove the heat and reheat the slide as needed to keep the slide steaming for about three minutes.  As the paper begins to dry add a drop or two of malachite green to keep it moist, but don't add so much at one time that the temperature is appreciably reduced.  DO NOT OVERHEAT.  The process is steaming and not baking.

5.  Remove the paper with tweezers and rinse the slide thoroughly with tap water.

6.  Drain the slide and counterstain 45 seconds with 0.5% safranin.

7.  Wash, blot, and examine.

8.  The vegetative cells will appear red and the spores will appear green.

Go To Results of Endospore Stain
Lab Procedures