Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It's 100% free, no registration required.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Is it possible to select from colonies only cells which are at a certain stage in the cell cycle? E.g. if I was trying to analyse expression of a number of genes during different stages of the cell cycle.

I could imagine that if this is possible, the selection mechanism might target cyclins, or use an artificial gene cassette controlled by them.

So for example, a method may attach some gene to a certain cyclin which protects against a substance that otherwise destroys the cell. We could then use that substance to destroy all cells which were not in the cell cycle stage that we want to look at, wash away their nucleic acids, and then extract the mRNA from remaining cells to analyse expression levels at this particular stage in the cell cycle. If we repeat that for the different stages, we should be able to get a nice picture of what is expressed when. Does any method like this exist or is commonly used?

share|improve this question

Depending on the stage of cell-cycle you are interested in, people often use the size/morphology of the cell as an indicator. Then you select cells with a cell sorter.

Another option is to specifically tag some cellular molecule that can give an indication as to the relevant stage and then sort the cells based on the tag. This does not necessarily have to be cyclins - for example if you are only interested in S/G2 you could tag the DNA or maybe histones.

share|improve this answer

You have correctly stated that we can monitor cell cycle stage by either monitoring protein (cyclin) levels or by following indirect methods such as green cassettes. One usually tries to monitor changing levels of:

  • G1 cyclins (D cyclins)
  • S-phase cyclins (cyclins E and A)
  • Mitotic cyclins (B cyclins)

Or one might try to modify the gene where these proteins are produced so that one can observe some unique behavior that highlights that particular stage of cell cycle is going on.

share|improve this answer
Thanks for the info! Though it doesn't quite answer what I wanted to know - I added more detail to my question as I can understand that I was a bit unclear. – Armatus Jan 6 '13 at 16:49

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.