Simple Stain

Now that we have a pure culture, we want to see what this bacteria looks like up close. To do this we need to stain the bacteria so they can be viewed under a microscope to see their structure and shape. A drop of water is placed on a slide, bacteria added and swirled in the water, fixed by letting the water air dry and running it through a flame. Then Gram’s Safranin (Red) stain and/or Crystal Violet (Purple) stain is applied, let dry, and rinsed.

Crystal Violet and Gram's Safranin Stains

Environmental Samples under low magnification:

Lauren's Env. Sample stained with Crystal Violet

                                           Kelley's Env. Sample. (Upper image under low power and lower image under oil immersion)

In order to manage a close up of the bacteria, we need to look at them using immersion oil. This oil has the same refractory index as the glass slide, and when it makes contact with the microscope lens, it prevents the light rays from bouncing or refracting out of the lens, giving a much sharper image.

Applying imersion oil to slide

Environmental Samples under high magnification using imersion oil:

Lauren's Env. Sample stained with Gram's Safrinin under high magnification using imersion oil