Glutathione S-transferase Mu 1?(GSTM1) belongs to the mu class. GSTM1 can detoxifying carcinogens, therapeutic drugs, environmental toxins and products of oxidative stress, by conjugation with glutathione. Besides, uncoupling Protein 1 (UCP1) has been identified as an interactor of GSTM1, thus a binding ELISA assay was conducted to detect the interaction of recombinant rat GSTM1 and recombinant rat UCP1. Briefly, GSTM1 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100uL were then transferred to UCP1-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-GSTM1 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody, wells were aspirated and washed 3 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50μL stop solution to the wells and read at 450nm immediately. The binding activity of of GSTM1 and UCP1 was shown in Figure 1, and this effect was in a dose dependent manner.