I need help in understanding some amplification data from qPCR assays.
when I perform amplification (cybergreen-based qPCR) on serial dilutions of cDNA (1:1, 1:10, 1:100) with some (gene) specific primer pairs, I systematically obtain the reversal of starting of the exponential phases: 1:1 related curve spreads AFTER 1:10, or 1:10 AFTER 1:100.
Given that there are no errors in pipetting or diluting... can someone help me in understanding this behaviour?
At the moment, I can only guess that some impurity in the cDNA samples can have random influence on amplification.
Also, I specify that peaks in melting curves looks good and possible shifts are small and not related to primer dimers.
I hope that someone can give me the right hints...