Screen shot from the Partec CyFlow flow cytometer showing flow histogram obtained from analysing Urtica dioica accessions 28-10 (peak 1, 2C=2.36 pg) and 37-6 (peak 2, 2C=2.59 pg) showing two distinct peaks and hence demonstrating genuine intraspecific variation in genome size between these two tetraploid individuals (28-10 and 37-6: see Table 3). The graph shows the relative fluorescence (indicative of DNA amount) in thousands of cell nuclei. The machine also gives summary statistics for the peaks. Note the very low coefficient of variation (CV%) of 2.48% and 2.89%.