While informative by itself, an absolute RFU presentation would be problematic to compare different assays due to inherent differences between them. Instead, a manual subtraction of the 1 st cycle RFU of "cDNA alone" control in each assay (e.g., "black" amplification profile in Figure ) from the rest of the amplification profiles seemed a more appropriate representation (Figure ). This was also beneficial in comparing and normalizing different assays since the "cDNA alone" control has been present in all studies and its 1 st cycle RFU remained of almost similar magnitude between different assays (please see uploaded raw data). Thus, the end-RFU of a baseline-subtracted "cDNA alone" control in an LRCA assay (e.g., 182 for black square profile, Figure ) and that of a "cDNA with HRCA" in an HRCA assay (e.g., 5168 for red circle profile, Figure ) was categorized as the absolute quantification of the NSA. Accordingly, this "baseline subtraction" measure was first applied in all the assays. In an ideal scenario without any NSA, both should be close to zero. Interestingly, we could not find prior literature reports concerning the baseline correction in RCA despite its importance in quantification.