N,N-Dimethylcasein is a chemically modified derivative of casein, primarily used in biochemical and biomedical research as a substrate for the spectrophotometric determination of enzyme activity, especially proteolytic enzymes. Its dimethylation enhances solubility and allows for easy monitoring of enzymatic hydrolysis via changes in turbidity or UV absorbance. It is employed in studies of cell adhesion, protein interactions, and enzyme kinetics. Additionally, its stable, protein-mimicking structure makes it suitable for applications in tissue engineering, regenerative medicine, and drug delivery systems. In materials science, it serves as a coating or model compound, and in some industrial contexts, it contributes to eco-friendly adhesives and coatings.