Are there any non lethal flurochromes for staining bacterial genomes?

September 28, 2007 6:50 PM

I wish to stain a colony of bacteria so that I can make relative measurements of their genome size, and I do not want to harm them in the process. Is this possible?
posted by paradroid to Science & Nature (3 answers total)

Best answer: I think this is tricky, as most DNA-binding dyes tend to be mutagenic and thus toxic to cells. Also, many of the commonly used DNA-binding dyes are not that cell-permeable.

The Molecular Probes handbook lists many DNA-binding dyes, some of which are cell permeable, and I think some of which are relatively non-toxic. See sections 8.1 and 8.6.

If you do find a non-toxic cell-permeant dye, beware that some will bind to RNA as well as DNA, and you'll probably need to do your own calibration of fluorescence instensity -> genome size.

Good luck.
posted by pombe at 7:00 PM on September 28, 2007

Response by poster: thanks. i should add that moderately mutagenic is ok, even desirable for my application, just can't be lethal.
posted by paradroid at 7:25 PM on September 28, 2007

Pombe's links point to SYBR Safe as a possibility. An MIT study of EtBr and SYBR Safe showed little RNA binding.
posted by Blazecock Pileon at 11:37 PM on September 28, 2007