Integrin Beta 1 (ITGb1) is a fundamental transmembrane receptor that mediates bidirectional signaling between cells and the extracellular matrix (ECM). As the most ubiquitously expressed β integrin subunit, ITGb1 partners with different α subunits to form functional heterodimers that regulate critical cellular processes including adhesion, migration, proliferation, and differentiation. This versatile receptor plays indispensable roles in embryogenesis, wound healing, and immune cell trafficking through its ability to transmit both mechanical and biochemical signals across the plasma membrane. The dysregulation of ITGb1 function has been implicated in various pathological conditions, particularly tumor metastasis, tissue fibrosis, and chronic inflammatory disorders. ITGb1 specifically combines with ITGa3 through non-covalent interactions to form the ɑ3β1 integrin heterodimer, a key laminin receptor that mediates cell-ECM adhesion and subsequent intracellular signaling cascades.Thus a functional binding ELISA assay was conducted to detect the interaction of recombinant human ITGb1 and recombinant mouse ITGa3 . Briefly, biotin-linked ITGb1 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100μl were then transferred to ITGa3-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 human ITGb1 and recombinant mouse ITGa3 was shown in Figure 1, the EC50?for this effect is 4.33μg/mL.