Peroxisome Proliferator Activated Receptor Gamma (PPARg) belongs to a large group of nuclear receptors controlling reproduction, metabolism, development and immune response. It is mainly expressed in adipose tissue, hematopoietic cells and the large intestine and it plays an important role in adipocyte differentiation, lipid and glucose metabolism, and modulation of immune and inflammatory reactions. Besides, Peroxisome Proliferator Activated Receptor Gamma Coactivator 1 Alpha (PPARgC1a) has been identified as an interactor of PPARg, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human PPARg and recombinant mouse PPARgC1a. Briefly, PPARg was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to PPARgC1a-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-PPARg pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 µL stop solution to the wells and read at 450/630 nm immediately. The binding activity of recombinant human PPARg and recombinant mouse PPARgC1a was shown in Figure 1, the EC50 for this effect is 0.03 ug/mL.