Growth Hormone (GH) is a 191-amino acid polypeptide hormone synthesized and secreted by somatotroph cells of the anterior pituitary gland. As a master regulator of somatic development, GH exerts its biological effects primarily through binding to the growth hormone receptor (GHR), thereby activating the JAK2-STAT signaling cascade. This activation stimulates insulin-like growth factor 1 (IGF-1) production in the liver while simultaneously promoting direct tissue growth effects.Besides,Erythropoietin (EPO) has been identified as an interactor of GH, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant bovine GH and recombinant mouse EPO. Briefly, GH was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to EPO-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-GH 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 bovine GH and recombinant mouse EPO was shown in Figure 1, the EC50 for this effect is 0.062µg/mL.