Growth Hormone Releasing Hormone (GHRH), also known as somatocrinin, is a peptide hormone secreted by the hypothalamus. It binds to specific receptors in the pituitary gland, stimulating the synthesis and release of growth hormone (GH), which regulates growth, metabolism, and cellular functions.Growth Hormone Releasing Hormone Receptor (GHRHR) is a transmembrane receptor located on the surface of pituitary cells. It has a specific binding site that can precisely recognize and bind to GHRH.Thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human GHRH and recombinant human GHRHR.Briefly, biotin-linked GHRH were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to GHRHR-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST 3 times and incubation with Streptavidin-HRP for 30min, then wells were aspirated and washed 5 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 GHRH and GHRHR was shown in Figure 1, the EC50?for this effect is 0.228ug/mL.