flow cytometry, a technique in which cells suspended in a fluid flow one at a time through a focus of exciting light, which is scattered in patterns characteristic to the cells and their components. They are often labeled with fluorescent markers so that light is first absorbed and then emitted at altered frequencies. A sensor detecting the scattered or emitted light measures the size and molecular characteristics of individual cells. Tens of thousands of cells can be examined per minute, and the data gathered are processed by computer.
