The Becton Dickinson FACSCalibur™ is an automated, four-color flow
cytometry system capable of analyzing and sorting cells. Flow cytometry
simultaneously measures and then analyzes multiple physical
characteristics of cells as they flow in a fluid stream through a beam
of light. The properties measured include relative size, relative
granularity or internal complexity, and relative fluorescence
intensity. These characteristics are determined using an
optical-to-electronic coupling system that records how the cell scatters
incident laser light and emits fluorescence.