mRNA levels, transcription or Gene expression? - (Nov/20/2008 )
Dear all,
I have a quick conceptual question, and would really appreciate if you could help me out.
I am extracting RNA from cells treated with 2 different drugs. I use trizol for extraction and then prepare cDNA using oligo-dT primers. The cDNA is later analysed by real time PCR and compared to a control.
What would be the most correct expression to use, in order to describe this experiment?
Measurement of…
a. "transcriptional change"?
b. "changes in gene expression"?
c. "changes in mRNA levels"?
d. "relative changes in mRNA levels"?
e. Any other suggestions?
I really appreciate your input!
All the best,
J.
I have a quick conceptual question, and would really appreciate if you could help me out.
I am extracting RNA from cells treated with 2 different drugs. I use trizol for extraction and then prepare cDNA using oligo-dT primers. The cDNA is later analysed by real time PCR and compared to a control.
What would be the most correct expression to use, in order to describe this experiment?
Measurement of…
a. "transcriptional change"?
b. "changes in gene expression"?
c. "changes in mRNA levels"?
d. "relative changes in mRNA levels"?
e. Any other suggestions?
I really appreciate your input!
All the best,
J.
I think most common use is b.
For fun, google each quoted phrase and look at the returned number of results. You may have a statistically more significant answer than mine.
If you do the exercise, post the results here too.
That's a really good question, Julianne, and one that more people should stop to think about. The best way to address this issue is to look closely at what the data from quantitative real-time PCR actually represent. The data show how much PCR product amplifies from a certain region of cDNA that is generated from RNA that possesses a poly-A tail and existing at one point in time. If transcription, RNA extraction, cDNA production, and PCR efficiencies are perfect, you could perhaps claim to be measuring differential levels of transcription (aka mRNA levels) in different samples. I don't like the use of the word "change" in your options. You don't actually measure changes in anything since your measurements only detect levels of one thing at one point in time. You will, of course, infer changes from the differences you see in your measurements. The most common misused expression involves claims of measuring gene expression. You need to measure protein levels for that. So I would vote for e. But I have no good suggestions that are 25 words or less. Perhaps "differential levels of transciption" would upset me the least.