In this video I'm going to show you how to do an endospor stain. Hello! First we need to put on our eye protection. Here's our endospor staining procedure. The first step is to apply the primary stain Malachite Green. This is done over a water bath for 3 to 5 minutes. The heat from the water bath will drive that green stain into the endospor. Next we'll rinse the slide with water and the final stop is to apply the counter stain. Saferin. This pink stain is a contrasting color to the green and the limparate color to the vegetative bacterial cells. We begin by applying the primary stain in a fume hood. Here's my prepared endospor slide. My unknown is in the center circle and my two controls are in the outer circles. I place my slide over the water bath and now I'm ready to apply the primary stain Malachite Green. I drip the Malachite Green directly onto my slide, making sure that each of those circles are completely covered with stain. Allow the stained slide to heat over the water bath for 3 to 5 minutes. It's important not to let that stain dry out so if it looks like it's beginning to dry out, you can apply more Malachite Green. After 3 to 5 minutes, I retrieve my slide, allowing any excess stain to drip off into the water bath. I then place the slide on a paper towel and take it back to my station to finish the stained procedure. The next step is to rinse the Malachite Green off the slide. After rinsing, I'm now ready to apply my counter stain, saffonin. The Malachite Green was easier to use than the original one. After rinsing, I'm now ready to apply my counter stain, saffonin. The Malachite Green was used to stain the endospores. The counter stain saffonin is used to stain the bacterial cells, a contrasting color. Once I've applied the saffonin to cover all 3 circles, all 3 bacterial smears, I wait 1 minute. Now it's time to rinse the saffonin off of my slide. After rinsing, I'm going to gently blot that slide dry. Don't rub the slide or you can wipe off the bacterial smears, just gently blot. Here's my finished slide. Here's another example of an endospore stained slide. I have my unknown smear in the center. To the left is my positive control, my known endospore producer. In the sample I use Bicillus subtilus. Here it is under the scope, under oil and immersion, magnified 1,000 times. The little green ovals are the endospores and the pink rods are the vegetative cells. The bacterial smear on the right is my nonendospore producer, which would be my negative control. In this case, I use Staphylococcus. Here's what my negative control looks like under the scope. This is Staphylococcus epidermidis. It does not produce endospores, so I see only pink vegetative cells. More seriously nerdy, amazing free stuff at scienceproffonline.com.