A technique for the production of small polymer microbeads (less than 150 mum diam.) utilizing electrostatic spraying is presented. Video and image analysis were performed to reveal details of the mechanism of droplet formation. Microbeads coated with poly-L-lysine were prepared and found to be effective as microcarriers for culturing surface immobilized insect cells to a high cell density (1.55 x 10(7) cells/ml microbeads).