Question about expanding the linear range for my standard curve dilution in Taqman probe qPCR? I am doing a 4-fold serial dilution using the Taqman probe assay to generate a standard curve dilution, and it was a multiplex qPCR. And I am trying to use the reagent and primers concentration from a paper, and the amount of concentration for the primers and reagents I used is the same as the paper. The sample I used Nanodrop result is shown attached. I am using 4-fold dilution (3ng-0.01ng), 1800 copies of DNA, and 2 copies. The paper uses plasmid 3.8kb length(10pg-1fg) 5-point dilution 10^6 copies DNA to 10^1 copies. And They are using 10-fold dilution. By looking at their standard dilution plot, in the high end (low CT, high input), and compared their plot and my plot, their slope looks steep in the high end, my plot looks flatten. The slope is about -3.7, and the qPCR amplification efficacy En is 88%. How to improve my standard curve in the high end makes the plot steep, improving my qPCR amplification efficacy? How to expand my linear range for my curve? I only can use the lower end (High CT, low initial input DNA amount) for now.