miRNA 3' end labeling - (Nov/11/2007 )
just a basic question: how does 3' end labeling of miRNAs in a total RNA sample work? How is it assured that only miRNA is labeled? Or is each RNA labeled and when for example doing microarray experiments anyway only labeled miRNA will then bind to LNA probes..
I guess you have to first isolate small RNA only and then label it. Not all of the samll RNA is microrna, but mostly is.
No, there are protocols where enrichment for small RNAs is not necessary.
Unfortunately, they don't write in their manuals how it works that only miRNA is labeled.
In theory every RNA molecule gets 3` labeled. In our lab we get a labeling efficiency of 60% (6 out of 10 RNA molecules will be 3` labeled on avarage)
Every LNA probe is desinged to reach the maximal delta Tm between an 100% match and one mismatch. So in theory only a 100% matched miRNA will hybridize to the LNA probe.
Not only the labeled miRNA will be hybridized also the not labeled one.
hope this answers your question