It is not a common probe for IF. If you like LifeTechnologies stains, you may want to check out their website for suggestions on nuclear dyes (see attached link). Chances are you would be able to get away with picoGreen, but it is NOT a cell permeable stain, and you will need to use some form of cell permeation technique (Detergents at 1/10th minimum micelle concentration, or dehydrating fixative (cold EtOH, Acetone, etc).

Good Luck 

https://www.lifetechnologies.com/us/en/home/references/molecular-probes-the-handbook/probes-for-organelles/nuclear-and-chromosome-counterstaining-and-nissl-stains.html

Thank you for your answer...I am actually trying to stain mitochondrial DNA, so I need a very sensitive probe. 

Olivia, a classic would be DAPI.

Hope that helps

Torsten

Torsten, thank you but in my experience DAPI is not sensitive enough to detect the mitochondrial DNA. Either a) the dye cannot get through the membranes to stain, or b) the intense nuclear signal "washes out" the much lower mitochondrial signal. 

Hey Olivia, I am not sure where you are with your project, but I did come across a paper where picoGreen was used to stain live cells mtDNA in culture. So to amend my answer above, yes picoGreen should work, and will work in living cells as well. The authors added 3 μl/ml of stock solution to their culture media for 1hr followed by washout for an additional 20min. 

Good luck

http://www.ncbi.nlm.nih.gov/pubmed/15652355

Yes. See the application in these two studies:

https://www.cell.com/cell-reports/pdfExtended/S2211-1247(18)31817-5

https://www.jci.org/articles/view/123319#sd

Olivia Harding Hi Olivia, did you manage to try the picoGreen to stain mtDNA? If yes, what was your experience? Or do you have other suggestions for some alternative stain of mtDNA except the previously discussed DAPI? Thanks. P.