JAK3 (Tyrosine-protein kinase JAK3) is a non-receptor tyrosine kinase that involved in various processes such as cell growth, development, or differentiation. Besides, STAM2 has been identified as an interactor of JAK3, thus a binding ELISA assay was conducted to detect the interaction of recombinant human JAK3 and recombinant human STAM2. Briefly, JAK3 were diluted serially in PBS, with 0.01%BSA (pH 7.4). Duplicate samples of 100uL were then transferred to STAM2-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-JAK3 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 JAK3 and STAM2 was shown in Figure 1, and this effect was in a dose dependent manner.