Monday, July 12, 2010

cell culturing

One of the idea things we would like to do with our machine is run real cells through it to test it out and see what kind of signals we get from the detector. In order to do this, we need to grow the cells ourselves, because it is much more practical than ordering a whole bunch of them and trying to keep them alive.

Growing cells, or "culturing" as it is usually called, is a very simple but specific process. You need to give the cells a place to be, and medium to grow in. Most importantly, you need to make sure that only your cells are growing, otherwise your culture won't be what you wanted it to, and this can really mess up an experiment. One of the PhD students in Dr. Bigio's lab showed us how to grow these cells. First, we needed to get a starter culture to begin with. These are kept frozen in a giant freezer at -80 degrees. We have to warm up these cells, so that they come out of their suspended animation and can grow and multiply in the medium. We can just do that in a water bath.

It is very important that we don't introduce any other types of cells into the medium, so everything has to be extremely clean, we carried all of our stuff to the cell culture room in its original packaging, sow e knew it was sterile. Here is the bucket with our pipettes (used to suck up liquid like the growth media) and our cell plates, all still in their sterilized containers.

We then just mix the cells with the media so there is a bout 10mL total, and let them grow! When they grow too much, they will sue up all the nutrients in the media, and need to be "split". This means that a portion of the culture is put into a new plate with more media that it can grow into. This is just like dilution of a chemical solution: we know that each plate is 10mL, if we have a full plate of cells and want to make 1:10 dilutions, how many plates would we need, and how much of the cell-solution and media would we need to use in each? Think about it for a little while, and you could be culturing your own cells!


So, remember how important it was to keep everything vclean and to not contaminate your cultures with any other type of cell? When we checked on our cultures to see if we needed to split them so they could grow more, we found this:

That, is mold. White fluffy mold growing in what is supposed to be filled with invisible little cells. When this happens, we need to dump it out and start all over with a fresh batch of uncontaminated cells. The plates need to be bleached before we can dump them though, and the reaction between the indicator and the pH change caused by the bleach can lead to some pretty interesting colors:

No comments:

Post a Comment