(sī-tŏm'ĕ-trē )

[ cyto- +_ -metry ]

The counting and measuring of cells.

flow c.A technique for analyzing individual cells passing through a detector system. In one method, the cells are tagged with a monoclonal antibody carrying a fluorescent label. They pass through the detector at about 10,000 cells per second. Flow cytometry has many clinical and research applications, including analysis of cell size, structure, and viability; examination of DNA and RNA in the cells; determination of pH in the cells; and chromosome analysis. Flow cytometry is also used to determine the percentages of cells in various stages of development in a population, making it possible to estimate the extent or controllability of a malignant tumor. Monitoring the number of populations of T cells, B cells, and T helper and suppressor cells and using that information to calculate the helper/suppressor ratio assist in determining the patient's immune status. Flow cytometry has been used in monitoring survival of transplanted organs and tissues such as bone marrow. SYN: cytofluorometry.

SEE: cell sorting.