Wallace Coulter
Wallace Coulter - Coulter orifice - 1956 -
(as early as 1948) - measured changes in electrical
conductance as cells suspended in saline passed through a
- Cells are relatively poor conductors
- Blood is a suspension of cells in plasma which is a relatively good conductor
- Previously it was known that the cellular fraction of blood could be estimated from the conductance of blood
- As the ratio of cells to plasma increases the conductance of blood decreases
