Immobilization of highly concentrated cell suspensions using the laminar jet breakup technique

The controlled breakup of a disturbed jet is a well-known technique for monodisperse particle production and has been well-investigated for Newtonian and viscoelastic fluids. For the immobilization of cells in beads of a hydrogel it has been observed that there is a maximum cell concentration beyond which a monodisperse bead distribution cannot be reached. Higher concentrations lead to irregular jet breakup and thus to droplet coalescence forming beads with double or triple volume. This maximum cell concentration has been investigated for different operating conditions using latex beads of different diameters as a model substance for cells and baker's yeast as a comparison. The maximum cell concentration where a monodisperse size distribution could still be achieved was increased using an electrostatic droplet dispersion system.