TABLE 2. Comparison of detection limits, limits of quantification for the whole method, EC50 values and assay time for the various in vitro assays Assay Cell Detection limit^a) (ng E2/l) LOQ^b) for the whole method (ng EEQ/l) EC50 (ng E2/l) Assay time (days) References ER binding 272 3162 953 or 17,705 1 2 Murk et al., 2002 Gutendorf and Westendorf, 2001 ER-CALUX T47D 0.1 0.001^c) 1.6 3 Murk et al., 2002 Vethaak et al., 2002 MVLN assay MVLN 1 4 Gutendorf and Westendorf, 2001 Chimeric receptor/ reporter gene assay MCF-7 HeLa HGELN 5 5 5.4 ~10 11 3 3 4 Zacharewski et al ., 1995 Balaguer et al., 1996 Gutendorf and Westendorf, 2001 YES Yeast 2.7 ~2.75 £ 1 3 ~2 0.03^d) 27 ~100 57 60 212 54 57 54 or 218 54 2 or 3 3-4 4-5 10 2 3 2 3 3 3 or 4 Murk et al., 2002 Witters et al ., 2001 Hugget et al., 2003 Kirk et al., 2002 Arijs et al., 2002 + pers. comm. Folmar et al., 2002 Beresford et al., 2000 Segner et al., 2003 Miller et al., 2001 Tyler et al., 2000 Andersen et al ., 1999 Arnold et al., 1996 E-screen MCF-7 0.27 0.07-0.14 1.3-2.2 0.3-2.7 1 8.7 0.03-1.9 1.7 6 6 8 6 6 5-6 Körner et al., 1998, 1999, 2000 Körner et al., 2001 Gutendorf and Westendorf, 2001 Folmar et al., 2002 Andersen et al ., 1999 Behnisch et al ., 2001 a) Detection limit not including concentration factors (see section 5.3.1).