Elastin (ELN) is an extracellular matrix (ECM) protein responsible for the extensibility and elastic recoil of many vertebrate tissues. ELN is abundant in elastic tissues, and tissues rich in elastin include the aorta and major blood vessels, the lungs, elastic ligaments, tendons and the skin. ELN can bind the elastin receptor complex and other receptors and stimulate migration and proliferation of monocytes and skin fibroblasts. Elastokines can also contribute to cancer progression. Deletions and mutations in this gene are associated with supravalvular aortic stenosis (SVAS), autosomal dominant cutis laxa. Decorin (DCN), an extracellular matrix (ECM) protein, is one of targets of ECM. Thus a functional binding ELISA assay was conducted to detect the interaction of recombinant mouse ELN and recombinant human DCN. Briefly, ELN was diluted serially in PBS with 0.01% BSA (pH 7.4). Duplicate samples of 100 μl were then transferred to DCN-coated microtiter wells and incubated for 1h at 37℃. Wells were washed with PBST and incubated for 1h with anti-ELN 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 450/630 nm immediately. The binding activity of recombinant mouse ELN and recombinant human DCN was shown in Figure 1, the EC50 for this effect is 0.068 ug/mL.