Poly-L-lysine is a nonspecific attachment factor for cells useful in promoting cell adhesion to solid substrates. It enhances electrostatic interaction between negatively charged ions of the cell membrane and the culture surface. When adsorbed to the culture surface, poly-L-lysine increases the number of positively charged sites available for cell binding. Polymers of both D- and L-lysine are used to coat solid surfaces.

Soluble in 50 mg/ml water. Typically, the effective coating solution concentration for culture dishes will be 0,3 to 0,5% and for histology slides at 0,1%.

It has been reported to improve the protein coating of ELISA plates. Other uses for poly-lysine have been reported as follow: Conjugation to methotrexate for increased drug transport, microencapsulation of islets, use in simple reproducible procedure for chromosomal preparations from a variety of tissues, immobilation of living cells in biocompatible semipermeable microcapsules, in the preparation of polycationic beads, and conjugation to albumin and horseradish peroxidase to enhance cellular uptake.

There is approximately one HCl per lysine unit. The HCl allows it to be a crystalline solid and soluble in water. To remove the HCl, solubilise the product in a neutral buffer and dialyse away the salts.