Day 6

Today we continued staining bacteria!

Preparing an Endospore stain:

To prepare an endospore stain we made a slide with fixed smear of bacteria. We then took a beaker and put water in it and boiled the water. We placed the slide on the beaker. We then placed paper on the slide and saturated the paper with malachite green. We stained for 5-6 minutes after the malachite green began to steam. We added additional stain as it evaporated making sure the stain does not dry.

We then removed the slide from the heat and removed the paper, and allowed the slide to cool.

Then we rinsed the slide with water for 30 seconds to remove excess malachite green. We covered the smear with safranin for 60-90 seconds. Then we rinsed the slide with water to remove excess safranin. Then we blotted the slide with pieces of bibulous paper and examined the side under the microscope suing oil immersion lens.

In examining the bacteria we were able to determine that our bacteria has no endospores.

 

 

  

Preparing a Capsule stain:

We prepared a capsule stain in order to view bacterial capsules and slime layers. We prepared a smear of bacteria in nigrosin by doing the procedure for a negative stain. We let the spread smear air dry and then covered it with safranin or crystal violet.

We then gently washed off the excess stain, and blotted the slide with bibulous paper.

We then examined it under the microscope with the oil immersion lens.

In examining the bacteria we were able determine that our bacteria was not capsulated. With this staining we were also able to confirm that our bacteria is rod-shaped.

Finding out what our bacteria consumes:

We did motility by adding our bacteria to it in a straight line by straight inoculation, and then placing it in the incubator.

We did Litmus milk, and added the bacteria to it by putting a loop full of bacteria into it and then incubating it.

We did gelatin by doing straight inoculation with our bacteria and putting a straight line of bacteria into the gelatin.

We had 3 plates: Casein, lipid and starch. On each plate we took our bacteria into a loop and drew the bacteria onto the plate in a snake shape, and then incubated it.