Insulin Like Growth Factor Binding Protein 2 (IGFBP2) is a member of the IGFBP superfamily, encoded by the IGFBP2 gene, with conserved cysteine-rich domains for IGF binding. Widely expressed in tissues like the liver, brain, and bone, it regulates the bioavailability and activity of insulin-like growth factors (IGFs) in physiological processes such as development, growth, and metabolism. Beyond IGF modulation, IGFBP2 exerts IGF-independent functions, including cell proliferation, migration, and differentiation, and its dysregulation is linked to cancer, metabolic disorders, and neurological diseases. As a key IGF regulatory protein, it modulates IGF signaling networks to maintain tissue homeostasis. IGFBP2 binds specifically to IGF1 with high affinity, sequestering it to control its bioavailability and downstream signaling.Briefly, IGF1 was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to IGFBP2-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-IGF1 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.Measured by its binding ability in a functional ELISA. When Recombinant IGFBP2 is lmmobilized at 2 µg/mL(100 uLwell), the concentration of IGF1 that produces 50% optimal bindingresponse is found to be approximately 0.523 µg/mL.