standard curve method RT-PCR

Hi,

I have been doing RT-PCR , and in I use standard curve method to quantify. in every PCR plate I run, i was taught that I should run corresponding REFERENCE GENE triplicates. Just not for any given cDNA synthesis, but for every PCR run I included a triplicate of 18S.

However i was recently told that this is a common misconception and that I do not need to do this for every plate, but only for a given cDNA synthesis, and then I can use these reference gene values to normalise genes of interest values.

I would be very gtrateful if any one who is using STANDARD CURVE METHOD COMMENT ON THIS.

thanks.

What are common sources of contamination in the qRTPCR? I too would be grateful for any feedback to this dilemma? thanks