Final answer:
Flow cytometry is an automated cell-counting system that can measure multiple parameters. It uses the 'flow' of cells through a narrow capillary, with the flow occurring in the flow cytometer.
Step-by-step explanation:
Flow cytometry is an automated cell-counting system used to quantify specific subsets of cells in complex mixtures by using fluorescently labeled antibodies. It detects fluorescing cells as they pass through a narrow tube one cell at a time. Flow cytometry can measure more than one parameter, such as the expression of multiple cell markers, by adding different fluorogens to the appropriate antibodies.
The 'flow' in flow cytometry refers to the movement of cells through a narrow capillary in single file. The instrument part through which the 'flow' occurs is called the flow cytometer.