JAK2 (Tyrosine-protein kinase JAK2) is a tyrosine kinase involved in various processes such as cell growth, development, differentiation or histone modifications. JAK2 is considered to associate with some type I receptors, including EPOR (Erythropoietin receptor), therefore participates in cellular signal transduction. Thus a binding ELISA assay was conducted to detect the interaction of recombinant human JAK2 and recombinant human EPOR. Briefly, JAK2 were diluted serially in PBS, with 0.01%BSA (pH 7.4). Duplicate samples of 100uL JAK2 were then transferred to EPOR-coated microtiter wells and incubated for 2h at 37°C. Wells were washed with PBST and incubated for 1h with anti-JAK2 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°C. Finally, add 50μL stop solution to the wells and read at 450nm immediately. The binding activity of JAK2 and EPOR was shown in Figure 1, and this effect was in a dose dependent manner.