Title: Determination of REP values for the CALUX bioassay and comparison to the WHO TEF values

Auteur(s): Brown D ; Chu M ; Van Overmeire I ; Chu A ; Clark GC ;  ; 

Year: 2001

Journal: Organohalogen Compounds

Subject(s): bioassay ; CALUX ; Luciferase ; dioxin-like compounds ; validation ; dioxin ; polychlorinated ; polychlorinated biphenyls ; Polychlorinated biphenyl ; PCB ;  ; 

Summary: Previously the CALUX® (Çhemically-Activated LUciferase expression) assay has been used to screen biological samples for contamination by dioxin-like compounds. A validation study has also been reported that examined ash, soil and exhaust gas samples by both gas chromatography/mass spectrometry (GC/MS) and the CALUX® assay in a double-blinded studio These studies indicated that the CALUX@ assay can be used to detect the presence of dioxin like compounds and is predictive of GC/MS results. In order to better understand the relationship between GC/MS results and in order to better characterize the responsiveness of the CALUX® bioassay, relative potency (REP) values were determined for each of the active polychlorinated dibenzodioxin and polychlorinated dibenzofuran (PCDD/PCDF) congeners and selected coplanar polychlorinated biphenyls (PCB). Generally the results were consistent with the consensus toxic equivalency factors (TEFs) reported by the World Health Organization3, but there were examples that diverged from the WHO TEF values. These differences seem to be related to the fact that the WHO TEF values incorporate uptake and metabolism whereas these processes do not appear to have a significant impact on the responsiveness of the CALUX® bioassay.