Help with some problems with Culturing Epithelial Cells - (Dec/25/2011 )

While watching a yale biomedical engineering lecture, ive stumbled onto the question:

bobby has been culturing epithelial cells for experiments that he is performing in the laboratory. He has subcultured the cells many times, and has always fed the cells the proper medium. He recently ran an experiment and found that his cells are not growing the way that he previously observed. What are some reasons why these cells may not be acting as they did previously?

Since this was a free online lecture, the answer was not provided and since i am having the same issue in my lab, I am wondering what is the cause for this phenomenon and if you guys may know the answer. Also, if possible, where would I be able to read more about this?

Thanks.

There are plenty of reasons and some of them are;

<*>Mycoplasma contamination
<*>Prolong trypsinization
<*>Altered culturing conditions
<*>Improper cell-freezing


and many others


Cheers!

Thanks for the response, Kamran. I will definitely look more closely into these possible reasons.

if they have been subcultured many times, senescence?

Genetic drifts that may occur through pro-long passaging could be a possible reason as well. Genome of cells aren't very stable outside of the body.

generally after culturing cells for one month or many passages, you need to re-thaw a new one just to keep all your results from this cell line reproducible.
I don't know exactly the reasons but genetic instability or something else could be one possible explanation.