Meteorin Like Protein (METRNL), corresponding to product code R740Hu, is a secreted cytokine with diverse physiological functions. It is widely expressed in tissues like adipose tissue, skeletal muscle, and the immune system. METRNL plays key roles in regulating energy metabolism, inflammation, and tissue repair. It is involved in activating beige adipocyte formation and enhancing energy expenditure, thereby participating in the regulation of body weight and glucose homeostasis. Additionally, it exerts anti-inflammatory effects by modulating immune cell responses. METRNL can regulate UCP1 (product code F557Mu) expression, promoting UCP1-mediated thermogenesis in adipocytes.Besides,UCP1 has been identified as an interactor of METRNL, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human METRNL and recombinant mouse UCP1. Briefly, METRNL was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to UCP1-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-METRNL 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 450/630nm immediately. The binding activity of recombinant human METRNL and recombinant mouse UCP1 was shown in Figure 1, the EC50 for this effect is 1.56416 µg/mL.