INDIGO's panel of PPAR reporter assays utilizes non-human mammalian cells engineered to express human peroxisome proliferator-activated receptors: PPAR(alpha) (NR1C1), PPAR(delta) (NR1C2), or PPAR(gamma) (NR1C3), all ligand-dependent transcription factors that are commonly referred to as PPAR(alpha), PPAR(delta) and PPAR(gamma). INDIGO's PPAR reporter cells include the luciferase reporter gene functionally linked to a responsive promoter. Thus, quantifying changes in luciferase expression in the treated reporter cells provides a sensitive surrogate measure of the changes in PPAR(alpha), PPAR(delta), or PPAR(gamma) activity. The principal application of this assay panel is in the screening of test samples to quantify any functional activity, either agonist or antagonist, that they may exert against the three human PPARs. PPAR reporter cells are prepared using INDIGO