The bioassay DR CALUX® (Dioxin Responsive Chemical Activated LUciferase gene eXpression) is used for quantification of dioxins/furans (PCDD/F) and dioxin-like PCBs (dl-PCBs). The difference between chemical analysis and the bioassay approach is illustrated in the figure below, based on EU-regulated 29 congeners of chlorinated compounds. DR CALUX measures the total toxic effect of a mixture (PXDD/F/dl-PXB) of dioxins, while chemical analysis (GC-MS) is focused on only certain compounds.