Inter- and intra-run coefficient of variation (CoV) for 10 μl and 5 μl reactions using seven ten-fold dilutions and normalized plasmid standards at 109copies/μl calculated using data from multiple runs. The data is presented for both copy number ( solid line) and Ct value ( dashed line). As would be expected, the CoV is higher for copy number than for Ct value and is also higher for inter-run than for intra-run. The CoV for copy number for both reaction volumes was consistently below 15% until at 107 copies for 5 μl reactions. The CoV for Ct value was consistently below 5% for both reaction volumes.