Take the 2-minute tour ×
Biology Stack Exchange is a question and answer site for biology researchers, academics, and students. It's 100% free, no registration required.

I am isolation RNA from Drosophila larvae brain with TRIzol method. What percentage of extracted RNA will be ribosomal RNA? I am only interested in mRNA, so I am trying to figure out whether I need to get rid of rRNA. Thanks

share|improve this question
    
Percentage of what? Total cell mass/volume? Of total RNA moieties? Of total nucleic acids? –  terdon Feb 25 at 12:53
    
Ratio of ribosomal RNA in total RNA if I rephrase it. –  golgicik Feb 25 at 12:57
    
OK, please edit your question to something like "I am extracting RNA using methodX, what percentage of extracted RNA will be ribosomal?" The percentages will also depend on the method used to extract the RNA. –  terdon Feb 25 at 13:03
    
I did, thanks.. –  golgicik Feb 25 at 13:07

1 Answer 1

up vote 3 down vote accepted

The protocol you are using will not only leave the sample with rRNA but also non coding RNA.

Many RNA protocols will separate mRNA by affinity of a carrier to the polyA tail. This protocol references an older paper that estimates that only 5% of RNA is mRNA. I'd be surprised if this ratio changed by more than 2-3 fold in drosophila.

I assume that %age is by weight but it could be a densitometry measurement which is similarly interpreted.

share|improve this answer
    
Thanks! As a subsequent question: Do you think that huge amount of rRNA will affect my downstream experiments such as RT-qPCR? I am only interested in mRNAs. –  golgicik Feb 26 at 9:39
    
I've not done qPCR. I would not hesitate to compare multiple standard protocols to get a better sample. Looking at a couple of qPCR protocols you're right I only see Triazol preparations used. PCR is pretty efficient as long as the primers are specific. Some more homework before doing the experiment won't hurt you :) –  shigeta Feb 26 at 14:35

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.