Preservation for RNA (including microRNAs – 75% ethanol series at -20°C)
To adequately preserve RNA, and particularly ensuring the preservation of microRNAs, multiple changes of ice-cold 75% ethanol can be used.
A) Keep materials on ice or ice-cold at all times.
B) It is best to preserve 2 “thumb-end size” pieces (or 4 1-cubic-cm pieces) in a 50 ml tube of ethanol. The larger volume ratio of ethanol:sponge, the better.
C) Put fresh tissue in 75% ethanol.
D) Change to fresh 75% ethanol after 15 minutes.
E) Change to fresh 75% ethanol after 1 hour.
F) Change to fresh 75% ethanol the next day.
G) Store at -20°C.