Leukemia inhibitory factor (LIF), is an interleukin 6 class cytokine that affects cell growth by inhibiting differentiation. LIF as a cytokine also has another fuction including: the growth promotion and cell differentiation of different types of target cells, influence on bone metabolism, cachexia, neural development, embryogenesis and inflammation. Besides, Colony Stimulating Factor Receptor, Granulocyte (GCSFR) has been identified as an interactor of LIF, thus a binding ELISA assay was conducted to detect the interaction of recombinant mouse LIF and recombinant mouse GCSFR. Briefly, LIF were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μL were then transferred to GCSFR-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-LIF 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 LIF and GCSFR was shown in Figure 1, and this effect was in a dose dependent manner.<br/>Figure. The binding activity of LIF with GCSFR.