RIPPA kit for RPA

[Qiacom]

We now also use biotin-labeled riboprobes for RPA with good results. 
Typically, less than 1% of the probe goes a long way.  But the most common
problem seems to be bad probes - ie incomplete transcripts, degraded
transcripts, etc.  As long as you gel purify (6% acrylamide/8M urea) yourprobe
first you should get clean RPA gels.  Omega Biotek has a nifty kit for gel
purification of RNA probes.

Good luck.
DB