To clean up 30ug of RNA try the following user-developed protocol:
DNase Digestion:
87.5ul eluate (take your 30ul RNA sample and add RNase free water to
make 87.5ul) 10ul Buffer RDD (in RNase free DNase kit) 2.5ul DNase I
stock solution.
Incubate on benchtop for 10 minutes and then proceed with RNA clean-up
protocol in the Rneasy Mini Kit.
The RNase-Free DNase set: Catalogue number 79254