04/30/2010 - Colorado State University, Department of Microbiology, Immunology and Pathology - Carolina Mehaffy
Today is Friday!. Yesterday I had a lot of fun. I went to the biosafety level III lab. In that lab we cultured Mycobacterium tuberculosis cells. Imagine that you can take a few cells of this bacteria and then put them in a liquid that has all the nutrients that bacteria need and then a couple of weeks later, you don't have a few cells anymore, but millions and millions of bacteria cells. This is what we call "culturing". Tuberculosis is a bacteria that can make you really sick, and because of this we did all the work in the level III lab. In this lab everything is very well controlled and safe, so scientists can still study these dangerous microbes without getting sick.
05/04/2010 - Colorado State University, Department of Microbiology, Immunology and Pathology - Carolina Mehaffy
Today I am having a great day too. First I cultured another bacteria that is harmless and can be used to insert small pieces of DNA from other organisms. This is the incubator where we grow the bacteria cells.
DNA is the material that carries all the information for a cell to function and live. The DNA is present inside of every single cell, including the cells in your body, in animals, insects and bacteria.The small pieces are called genes and they carry very specific information. For example, some of you have green eyes, and some blue or brown. Do you know what make you have blue, brown or green eyes?. Your genes!!!.
After growing the bacteria I added some chemicals to the cultures to break the cells and obtain their DNA. The DNA is very very small, and to see it I had to mix it with a fluorescent dye and separate it from other molecules in a gel. The gel is like a square piece of jello and you can see it in the picture below.
We also mixed the DNA with a blue dye before putting all our samples in the gel.
After putting the DNA in the gel I took it to the ultraviolet light chamber. Remember that I had mixed the DNA with a fluorescent dye, so if you see something fluorescent in the gel, that is the DNA.
And we did!!!. GREAT SUCCESS!!. I extracted DNA from bacteria cells!.
05/05/2010 - Colorado State University, Department of Microbiology, Immunology and Pathology - Carolina Mehaffy
Today is my last day in the Microbiology lab. I had a very fun week and I learnt a lot of new things. One of the big activities in a Microbiology lab is to obtain proteins from bacteria cells. Remember about DNA and genes?. Well, the information that is present in the genes helps the cell to make proteins, one gene for each protein. Bacteria have between 3000 and 8000 genes/proteins, and some of them are very important for the bacteria to survive inside our bodies. In order to develop new cures and treatments, it is important to know more about these proteins.
In this picture I am using a Fermentator which function is to grow bacteria in large quantities. After this, we can extract the proteins from the bacteria and start to study them.
Because one cell has so many proteins, it is difficult to study all of them at once. Therefore, we need to separate them to obtain samples with just a few or sometimes only one single protein. To do this I used an equipment called High Performance Liquid Chromatography or "HPLC". In this machine we use a very long and thin tube that has been filled with an especial material called "resin". When the proteins are passed through this resin, some proteins run faster or slower. You can think as if this was a car race, but instead of cars you have proteins. While some cars will go faster through the obstacles, others will take more time. The faster ones will reach the end of the tube in less time, allowing us to collect them before the slower ones get there.
This is the picture of the HPLC when I was separating the proteins.
Finally, after the proteins have been separated we stored them in a -80C freezer. This temperature is equal to -112 degrees Fahrenheit. BBRRR. It is cold in here!!!, but the cold temperature helps preserve proteins, DNA and other products from cells.
Finally, in my last day we had a meeting to talk about the important work that I did during this week. Talking to other scientist is fun, and also very important because we discuss new experiments and new ideas and that helps science to advance every day.
