A volume-activated cell sorter.

A sorter that is activated by the resistance pulses of a Coulter orifice (volume detector) has been developed. The problems arising from the distortion of the volume signals produced by the electric droplet forming and charging voltages are avoided by special shielding and grounding of the volume detector. Experiments with beads and leukocytes are described. The maximal processing rate at this time is 2000 cells/sec, the purity of sorted fractions is better than 97%, and the viability of sorted cells is better than 80%.