Colorado State University, Ft Collins, Colorado


11/8/10-11/15/10, Colorado State University, Infectious Disease Research Center

 

This week I'm back in Fort Collins at Colorado State University to visit another microbiologist, Dr. Brian Kvitko, at the Infectious Disease Research Center (IDRC) at the Foothills Campus. The scientists here study many different dangerous bacteria that can cause diseases.

 

To help keep everyone safe, all the doors are locked with key cards. I got a special visitors pass made!

 

I already learned a lot about DNA from Dr. Carolina Mehaffy in April. This week I'm going to learn about making gene knock out bacteria. If a microbiologists wants to find out what a gene does, one of the best ways to do it is to break that gene. They can do this by removing the DNA that carries the gene. They call this process "knocking out". Once you knock out a gene you study the knock out bacteria and determine if they behave differently than the original bacteria. If you find a difference you can make a hypothesis that the broken gene is important for that particular behavior.

 

A natural gene knock out can be seen in people and animals with Albinism. They carry a broken gene for making pigments.  Because they can't make pigments they have very pale hair, skin and eyes.

 


 

To knock out a gene in bacteria microbiologists build special small circular pieces of DNA called plasmids. Dr. Kvitko already built some plasmids for me to use. I'm very excited to try and knock out some genes!

 

First I need to put on some Personal Protective Equipment. PPE for short.


 

We put on scrubs and disposable gloves,

 

a face mask and hair net,

 

and lastly we put on a Powered Air Purifying Respirator. PAPR for short.

 

The backpack filters the air and pumps it into the hood so that we can breathe safely and comfortably.

 

Here I am with Dr. Kvitko in the training lab.

 

We did our work in a biosafety cabinet to add an extra level of protection. The biosafety cabinet controls and filters the air to keep it clean.

 

The knock out plasmid carries a gene to produce a blue pigment on special petri plates. When the plasmid is put into the bacteria to knock out the gene the bacteria turns blue. So, blue bacterial colonies show that we have knocked it out successfully. It worked!


 

Then we used some other petri plates to study how the bacteria behave under different conditions

 

This gene is involved in antibiotic resistance. The strip on the petri dish has antibiotics in it.  The gene knock out bacteria on the left won't grow near the antibiotic strip while the original bacteria on the right grow very well. These gene knock out bacteria are more sensitive to antibiotics so antibiotic treatment would be more effective.

 

This is a special petri plate to study iron usage. The plate has a dye in it that turns blue when it binds with iron. When bacteria use the iron the dye changes color to pink. The original bacteria on the right can use iron so they create pink halos around the bacterial colonies.  The gene knock out bacteria on the left can't use iron so they don't make pink halos. Iron is important for all living things so our gene knock out wouldn't be able to grow inside a person or cause disease very well.

 

I had a great time learning about biosafety and making gene knock out bacteria this week. I wonder what I'll get to do next?