Figure 2

Efficiency of amplification can be described as a function of fluorescence with a Gauss peak or a logistic peak model. For each amplicon described in Table 2 (same order, left to right corresponds to top to bottom), the third fluorescence curve (arbitrarily chosen; numbering refers to the Excel raw data file [see Additional file 5]) was analyzed. After subtraction of linear background, EA was calculated as F_i/F_i-1 ratio and plotted against fluorescence (F_i) as shown. To avoid confusion, points with F_i < 0.1 are not displayed; most of these, because of large errors in EA, lie outside the y axis range. The line graphs were drawn with the Gauss peak function (upper row) or the logistic peak function (lower row). Note that function parameters were not fitted to the points shown, but determined by our stepwise PCR simulation approach based on the raw fluorescence versus cycle number data. Open circles represent data that was not used for fitting.