Growth Hormone (GH), also known as somatotropin, is a peptide hormone synthesized and secreted by the somatotroph cells of the anterior pituitary gland. It plays a pivotal role in growth regulation, metabolism, and cellular repair across multiple tissues. GH exerts its effects both directly and indirectly through the stimulation of insulin-like growth factor 1 (IGF-1) production in the liver. The hormone binds to the growth hormone receptor (GHR), a member of the cytokine receptor superfamily, activating the JAK2-STAT signaling pathway to regulate gene expression. GH secretion is pulsatile, primarily controlled by hypothalamic growth hormone-releasing hormone (GHRH) and somatostatin. Beyond its growth-promoting functions, GH influences lipid metabolism, glucose homeostasis, and immune function.Besides,Prolactin (PRL) has been identified as an interactor of GH, thus a functional binding ELISA assay was conducted to detect the interaction of recombinant rat GH and recombinant pig PRL. Briefly, GH was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to PRL-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 rat GH and recombinant pig PRL was shown in Figure 1, the EC50 for this effect is 0.135 µg/mL.