Poly-L-Lysine is widely used as a coating agent to enhance cell adhesion on surfaces, particularly in cell culture applications. It promotes the attachment of cells to substrates, improving the growth and stability of cell lines in laboratory settings. Additionally, it is employed in the preparation of slides for microscopy, where it helps in the immobilization of tissue sections or cells for detailed analysis. In the field of biotechnology, Poly-L-Lysine is utilized in the development of biosensors and diagnostic devices, where it aids in the binding of biomolecules to sensor surfaces. It also finds application in gene delivery systems, acting as a vector to facilitate the transfer of genetic material into cells for research or therapeutic purposes. Furthermore, Poly-L-Lysine is used in the food industry as a preservative to extend the shelf life of certain products by inhibiting microbial growth. Its versatility and effectiveness make it a valuable component in various scientific and industrial applications.