Figure 3
From: Method validation of circulating tumour cell enumeration at low cell counts
Amelioration of inter-operator variability in CTC enumeration in patient samples at low cell counts. Between-operator error was calculated as the coefficient of variation (CV) in the mean cell count obtained by a panel of analysts enumerating CTC in 38 different cancer patient blood samples. (a) Inter-operator error for all 6 operators. (b) Reduced level of error obtained when only analysts 1, 4 and 5 (see Figure 2) who had demonstrated consistency were included. The 30% error line and 5 CTC line are shown for reference.