Table 4.

Comparison of in vitro assay for dichloro diphenyl trichloroethane (DDT)

Test chemicals	Yeast assay	E-screen assay	STTA assay
	Coldhama logRP	Sotob logRPP	This study logRTA
17β- estradiol	2	2	2
Dichloro diphenyl trichloroethane (DDT)	−4.52	−4	−2.76

^a: data from Coldham et al. (1997), ^b: data from Soto et al. (1995).

Abbreviations: E₂, 17β-estradiol; RP, relative potency compared to E₂ (100) by molar mass determined with the recombinant yeast bioassay; RPP, relative proliferative potency is the ratio between 17β-estradiol and xenoestrogen doses needed to produce maximal cell yields ×100; RTA, Relative transcriptional activation.