Timeless Storing of Bacteria and Culturing an Anaerobic Bacteria

This class we took a break from staining and made various cultures of our bacteria. In past blogs, we described storage of the bacteria in a refrigerator; however, this class we discovered a technique in which we could save our bacteria FOREVER! We know our children's children are going to come back wanting to see this sample! Using this method we are able to cryoprotect the bacteria. Bacterial membranes are delicate already, but when placed in a refrigerator these membranes may break from rapid cooling. Using the chemical Glycerol halts this process.

In order to begin our cryprotection, we first measured 300microLiters of 100% Glycerol using a pipet. Then we proceeded to empty the contents of the pipet tube into a small storing vesicle.

Second, we discarded the plastic pipet tube and attached a new sterilized tube to the tip. This prevented contamination of the bacteria and chemicals. After, we measured 700microLiters of the bacteria broth, making sure to mix the broth thoroughly before drawing the bacteria into the pipet tube. We added this sample to the Glycerol, mixing it by drawing and emptying the contents of the vesicle.

We labeled it and then stored it within a -80 degree Celsius storage unit. Keep tuning into the blog in order to find out if our bacteria survives until the end of the semester!

Culturing an Anaerobic Bacteria: 


To determine if our Unknown "F" Bacteria is Anaerobic (thrives better without Oxygen) we inoculated it into a Thioglycollate Broth. This chemical reacts with Oxygen to form water; where Oxygen is present in this broth the broth appears red.

Notice the red color at the top of each of the test tubes; this is where the Oxygen is present within the broth.

Using the simple aseptic technique, we isolated a sample of "F" into the broth and placed it into a 37 degree Celsius incubator. We are going to leave it to culture until next class where we will determine whether our bacteria is aerobic or anaerobic. This will be identified as to where the bacteria grows: in the red or yellow portion of the broth (Oxygenated or Deoxygenated respectively).

We also conducted a GasPak Anaerobic System to check the requirements of Oxygen in our bacteria. To do this we prepared a nutrient agar plate of our sample using the aseptic technique.

The GasPak (due to its catalyst Palladium) reduces Oxygen and produces Carbon Dioxide in the container. If our bacteria thrives in this container by next class, then we will know that it does not need Oxygen in order to grow and reproduce.

See you next time when we unravel the mystery of Oxygen intake of our Bacteria!