Fibroblast Growth Factor 7 (FGF7), also known as keratinocyte growth factor (KGF), is a paracrine signaling protein. It is mainly secreted by mesenchymal cells and specifically acts on epithelial cells. FGF7 plays crucial roles in cell proliferation, migration, and differentiation during development, tissue repair, and regeneration.FGF7 binds to Fibroblast Growth Factor Receptor 2 (FGFR2), particularly the IIIb isoform. This binding initiates a series of signaling cascades that regulate cellular functions essential for tissue homeostasis.Thus a functional ELISA assay was conducted to detect the interaction of recombinant human FGF7 and recombinant rat FGFR2. Briefly, FGF7 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to FGFR2-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-FGF7 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody for 1h at 37℃, wells were aspirated and washed 5 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50 μL stop solution to the wells and read at 450/630nm immediately. The binding activity of recombinant human FGF7 and recombinant rat FGFR2 was shown in Figure 1, the EC50?for this effect is 0.050ug/mL.