TF (Tissue factor) also known for platelet tissue factor, factor III, thromboplastin, or CD142, is a cell surface glyprotein present in subendothelial tissue and leukocytes. TF is necessary for the initiation of thrombin formation from the zymogen prothrombin. It has been proven that EGF can bind with the TF on the hemangioendotheliocytes. Thus a binding ELISA assay was conducted to detect the interaction of recombinant rat TF and recombinant rat EGF. Briefly, TF were diluted serially in PBS, with 0.01%BSA (pH 7.4). Duplicate samples of 100uL TF were then transferred to EGF-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-TF 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 TF and EGF was shown in Figure 1, and this effect was in a dose dependent manner.