CALUX® assays may be used for testing of single compounds as well as complex mixtures. The cells are cultured in well plates (usually 96 or 384 wells), which allows for increased throughput and automated handling. Subsequently, they are exposed to a dilution series of the test compound or a dilution series of an extract of the test sample. Along with the test samples, the cells are also exposed to a concentration series of a reference compound. After a certain exposure time, the light production in the individual wells is quantified using a luminometer. The activity evoked by the test compound or test sample is subsequently derived by interpolation in the response curve of the reference compound and is expressed in equivalences of this reference compound.
All CALUX®-based assays and most other cell-based assays can be run in two different modes, allowing to distinguish between agonists and antagonists. In the antagonistic mode competition with the reference compound is assessed.