In article <4ad9fc$km2 at dub-news-svc-2.compuserve.com>, 100414.220 at compuserve.com (Stefan Kley) says:
>>I have a problem with ethidium bromide. I ran a PAGE today to check
>the integrity of a few cDNA probes that I'm about to use in Northern
>Hybridisations. In order to visualize the DNA with UV light, I put the
>gel into an ethidium bromide bath for 45 minutes after the run.
>However, under UV light, the gel appeared empty, lacking a signal even
>from the slot where I loaded the DNA standard.
>>I always incoorporate the EtBr into the gel just before I pour it.
The gels I use for DNA analysis are made from agarose and I don't know if
you can do this with acrylamide. Anyway, I use 1uL of 10mg/mL EtBr for
every 20mL of gel. Also, I add the same concentration of EtBr into the
running buffer (TAE) since EtBr will run the opposite way to DNA on a gel.