Hydrodynamic focusing and electronic cell-sizing techniques.

The technique of hydrodynamic focusing, used to improve the resolution of the Coulter counter for the sizing of bacteria, was examined. Latex particles of 0.26 mum to 6.7 mum volume were used to examine the characteristics of the system with and without hydrodynamic focusing. The system then was evaluated for sizing mixed bacterial populations as well as single populations. Possible applications are also discussed.