Table 1.

Data point distributions investigated in the simulated concentration–response curves

Highest concentration	Dilution factor	Replicates per dilution	Lowest concentration	pEC50 (mean ± SD)	Slope (95% CI)
1 × 10−6	1:3	1	1.7 × 10−11	8.53 ± 0.12	0.56–1.55
1 × 10−7	1:2	1	9.8 × 10−11	8.51 ± 0.15	0.57–1.76
4 × 10−7	1:2.5	1	4.2 × 10−11	8.51 ± 0.12	0.61–1.63
1 × 10−6	1:16	2	1.5 × 10−11	8.52 ± 0.13*	0.47–2.10
1 × 10−6	1:10	2	1.0 × 10−10	8.53 ± 0.13	0.65–1.54
1 × 10−7	1:6	2	7.7 × 10−11	8.51 ± 0.13!	0.44–2.04
1 × 10−7	1:10	3	1.0 × 10−9	8.50 ± 0.12	0.64–1.50

Note a ‘buffer control’ (i.e. no agonist added) was included for every simulated curve with the same number of replicates as all other dilutions. The pEC₅₀ and slope columns of the table summarize the variability in the estimates of these parameters for the fitted curves in each simulation.

^*Seven curves in this set could not be fitted.

^!One curve in this set could not be fitted.