minimum mRNA concentration for RT-PCR - (Jan/09/2008 )

hello..does anyone know what is a minimum mRNA concentration for efficient RT-PCR? tnx

Total RNA or poly-A?

I use 1ug of total RNA. You can obviously use less but the final amount of cDNA will also decrease.
It depends on how much cDNA you'll need...

Theoretically, one copy of a single transcript can be amplified given enough cycles in the PCR. Like ambrosio, I generally to use 1ug for RT with an oligo-dT(15) primer, though I've had success with much less input(~30ng) obtained from laser micordissected samples.

thanks

We do RT-PCR on viral RNA from plasma and can get amplification when we add less than 20 copies (in case the sample was well preserved of course).