Amplified Recombinant Cell Bioassay for the Detection of Dioxin and Related Ah Receptor Ligands

Tech ID: 21033 / UC Case 2009-507-0


A researcher at the University of California, Davis has developed and characterized a new CALUX bioassay for the detection of lower concentrations of dioxins and dioxin-like chemicals within a sample.

  • Non-exclusive licenses are available for UC's property rights in this dioxin-detecting cell bioassay and patent rights in the luciferase reporter gene as it is utilized within the dioxin-detecting cell bioassay.
  • This cell bioassay system also contains components owned by the Promega Corporation. Licensees can acquire Promega permissions relevant to practicing this invention by executing a contract services agreement directly with Promega. UC can provide interested parties with a draft license agreement as well as a sample of the Promega contract services agreement.

Full Description

The Ah receptor (AhR) is a ligand-dependent transcription factor that mediates the ability of dioxin and related halogenated aromatic hydrocarbons (HaHs) to induce gene expression and to produce toxicity. Cell-based bioassays for dioxin-like chemicals (commonly referred to as CALUX bioassays) respond to dioxins and related chemicals with the induction of luciferase in a time-, dose-, AhR-, and chemical specific manner. While high-resolution instrumental analysis methods are the gold standard method for detection of dioxin-like chemicals and provide very accurate measurements of HAH presence, these procedures require expensive instrumentation, are time-consuming, and are impractical for large-scale screening analysis. There is a need for rapid, inexpensive and accurate methods for the detection and quantification of HAHs, such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) and related chemicals in environmental, biological, food and other matrices.

This invention provides an improved CALUX cell-based reporting system meeting this need. The current invention outperforms currently available cell bioassay systems in that it can detect dioxins and related dioxin-like chemicals at substantially lower concentrations (10-100 fold lower) and a significantly higher assay response than that of other bioanalytical systems.


  • Detection and relative quantitation of dioxin and dioxin-like chemicals in a wide variety of matrices, including primary matrices of concern such as food, feed, biological (tissue, milk and blood) and environmental samples
  • High throughput screening applications.


  • 10- fold to 100-fold increase in the minimal detection limits for dioxin and related chemicals
  • Dramatically enhanced overall response compared to other bioanalytical methods
  • Rapid and very low cost
  • Mouse, rat and human hepatoma cell lines, stably transfected with the AhR-responsive CALUX luciferase reporter plasmids, of this invention have dramatically improved sensitivity and reporter gene responsiveness to TCDD and related AhR agonists.
    • Improved luciferase activity observed at all inducer concentrations.
    • Increased activity and sensitivity allows for more accurate determinations of the induction response at the lower end of the concentration response curve, and results in a lower limit of chemical detection with these new cells
    • Can be used in a range of microplate formats (96 to 1536 well), reducing the amount of sample and reagents needed for cell growth and analysis while also reducing analysis cost and increasing sample throughput.

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  • Denison, Michael S.

Other Information


dioxin, food safety

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