These values for the initial rate I and half-life t1/2 depend on the concentration of anionophore used in the experiments. For the comparison of compounds that were tested at different concentrations, the specific initial rate [I] could be used, which is obtained upon dividing the initial rate by the transporter to lipid concentration. This specific initial rate [I] is based on the assumption that the initial rate increases linearly with the anionophore concentration. The deviation from this linearity can be observed and might have different causes. In some cases, transport at high concentrations of anionophore is so fast that other processes, such as the homogenisation of the sample after NaCl pulse addition or the integration time of the spectrometer become rate limiting. This would give lower specific initial rate values at higher concentrations. On the other hand, at very low anionophore concentrations, little curvature is observed and the impact from the initial quenching typically dominates the curvature, giving values that do not represent the true transport rate. Thus, the described quantification of transport via fitting and calculation of t1/2, I, or [I] is only valid if clear transport is observed and transport is not too fast. Alternatively, data from the lucigenin assay can also be analysed via a Hill plot analysis. Experiments using the lucigenin assay with giant unilamellar vesicles (GUVs, ~20 µm diameter) and confocal fluorescence microscopy made it possible to analyse the transport of chloride into individual GUVs (rather than over the ensemble of LUVs), confirming a linear relationship between the half-life of transport and the diameter of the GUVs, and allowing to estimate the rate per individual transporter.