How much RNA at least on agarose gel? - (Apr/04/2008 )

Hi,
I extracted RNA from rat brain's dissected tissue and the amount of RNA is very low!!! I would verify the integrity of RNA by agarose gel but I don't how mach RNA at least I have to load... can someone help me?
Thanks in advance

-ros75-

usually i load 1 µg RNA on a mini gel but i think you can go down to 0.5 or 0.25 µg if your RNA is not degraded.

-Ned Land-

you could probably get away with as low as 100ng, but that's pushing it. Do you really need to see it? Or can you just spec it for the concentration? If you have a DNA core facility where you work they might have a bioanalyzer which won't take much RNA and they can determine the integrity of it for you

-h2so4hurts-

I loaded into gel 250ng and i saw good RNA.... but i saw 4 bands:

?
28S
18S
tRNA (micro)

If i remember right DNA contamination is between 28S/18S, isn't it? What is the first band?

-ros75-