Human Quant. PCR cDNA Control
ehovig at radium.uio.no
Tue Feb 14 17:04:30 EST 1995
In article <3hq92n$q09 at cc.tut.fi>, bltihi at uta.fi (Timo Hiltunen) wrote:
> Pat Charmley (patcharm at u.washington.edu) wrote:
> : Dear Everyone,
> : I'm looking for a good PCR primer set for a human "structural gene" that
> : can be used as an internal control in my cDNA PCRs from various tissues.
> : I've read that actin is inducible, and thus I'm not interested. I've
> : heard that GAPDH is a good and stabley expressed gene. Does anyone have
> : a good reference, or personal experience?
> GAPDH is not stably expressed in the samples that we have analysed.
> Up to 5-fold induction seems to be possible.
> Anyhow, GAPDH has been rather widely used, and in some cases may be stably
And my opinion, although it does not weigh all that much, is that it will
not be possible to find such a stable cDNA. And it will anyway not be
possible to ***prove*** that anything is stable, as long as there is no
stochiometric relationship known between a given gene copy number, its
regulation, and cell status. What one can do is either pretend that such a
relationship exists ("a number of people are are using gene X, therefore
it must be usable, or at least referees will likely not mind"), or test a
number of high, middle, and low expressed transcripts to get a general
impression of cellullar status, or something like that. The same goes for
northerns. And consider a 5-fold variation: how will such a variation give
sensitive results when covaried with often very unreliable
semiquantitative rtPCR assays like limited cycle number. Not exactly
Eivind Hovig PhD email= ehovig at radium.uio.no Dept. of Tumor Biology
S=EHOVIG; OU=radium; O=uio; ADMD= ; PRMD=no Inst. for Cancer Res.
Phone:-47-22935416 The Norwegian Radium Hosp.
Fax: -47-22522421 0310 Oslo, Norway
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