How do I determine the linear dynamic range of my qPCR or qRT-PCR assay?
FAQ ID -2696

Prepare five (5) 10-fold serial dilutions of cDNA template known to express the gene of interest in high abundance. Use each serial dilution in separate real-time reactions, and determine their threshold cycle values. In a base-10 semi-logarithmic graph, plot the threshold cycle versus the dilution factor and fit the data to a straight line. The linear range of this plot is the linear dynamic range of the qPCR assay.