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 mouse GH and recombinant rabit PRL . Briefly, biotin-linked GH were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to PRL-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 recombinant mouse GH and recombinant rabit PRL was shown in Figure 1, the EC50 for this effect is 0.74 µg/mL.