The techniques of flow cytometry are ideal for evaluation of functional properties of live cells. One unique aspect of flow cytometry is that it allows the measurement of particular aspects of a single cell, regardless of the composition of the suspension or the heterogeneity of the cell population. Additionally, because light scatter is by nature of flow technology an integral measurement, it does not negatively interfere with fluorescence measurements as would occur using bulk fluorometry. Thus, flow cytometry can use scatter to identify a population, fluorescence properties to identify a response, and time to evaluate the kinetics of this response. Examples of this system would include the measurement of the oxidative burst of phagocytic cells, changes in calcium flux, alterations in membrane potential of activated cells or efflux pumps eliminating a drug or dye.
