Table 2.

Transport ratio and z-factor determined in A431-OATP cells.

	Transport ratio compared to control			z-factor
	1B1	1B3	2B1	1B1	1B3	2B1
Fl-MTX	2.14 ± 0.44	2.49 ± 0.72	1.24 ± 0.16	0.59	0.77	−1.80
Zombie Violet	11.05 ± 2.47	6.03 ± 1.43	14.65 ± 2.47	0.61	0.61	0.71
Live/Dead Violet	2.03 ± 0.59	1.33 ± 0.21	3.50 ± 0.53	0.55	−0.42	0.79
Live/Dead Green	3.82 ± 0.51	6.58 ± 1.73	6.74 ± 2.82	0.84	0.76	0.62
Cascade Blue	10.79 ± 2.46	1.71 ± 0.16	7.31 ± 2.17	0.73	0.26	0.66
Alexa Fluor 405	5.32 ± 1.22	4.65 ± 0.51	5.46 ± 2.46	0.59	0.64	0.57

A431 cells (seeded in 96-well plates) were incubated with the dyes at pH 5.5 for 30 minutes in order to reach maximum fluorescence signal. Data were calculated from at least 3 independent measurements. Dyes were applied in the following concentrations/amounts: Fl-MTX 1 µM (1B1 and 1B3) and 4 µM (2B1); ZV, LDV and LDG 1-1 µl; CB and AF405 10 µM (1B1 and 2B1) and 20 µM (1B3). A z-factor above 0.5 is defined as an excellent assay³⁷. Dyes defined as best candidates for HTS are indicated in bold.