What does cytometer mean?
A cytometer is a scientific instrument used to count and analyze cells. The dominant form today is the flow cytometer, which draws cells through a narrow channel in single file, illuminates each one with lasers, and records how the light scatters or fluoresces — revealing a cell's size, granularity, and the presence of specific molecules tagged with fluorescent markers. This lets researchers and clinicians rapidly profile millions of cells, distinguishing cell types in blood, identifying cancers such as leukemia, measuring immune responses, and sorting particular cells for further study. The word derives from Greek roots: kytos ("cell") plus metron ("measure"). Cytometers are indispensable in hospitals, research laboratories, and biotechnology, where they turn what was once slow manual microscopy into fast, quantitative analysis. Though highly technical, the term is central to modern diagnostics and cellular science.
nounAn instrument used to count and analyze cells, typically by suspending them in a fluid stream and measuring their physical or chemical properties, most commonly via fluorescence and light scattering as in flow cytometry.
- An instrument for counting and analyzing cells, especially one that measures cells in a moving fluid stream using optical detectors (a flow cytometer).
- More broadly, any device for counting cells, including older manual counting chambers such as the hemocytometer.
"The lab technician calibrated the flow cytometer before running the blood samples."
"Researchers used a flow cytometer to identify abnormal white blood cells in the patient's sample."
"Before automated instruments arrived, technicians counted blood cells by eye using a hemocytometer under a microscope."
Regular plural; used when referring to multiple instruments, e.g. across different labs or models.
"Both cytometers were serviced last week to keep their laser alignments accurate."
A modern flow cytometer can sort thousands of individual cells per second — picking single cells out of a rushing liquid jet with laser precision.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cytometer
The term "cytometer" combines the Greek root kytos, meaning a hollow vessel and adopted by biologists for "cell," with metron, meaning "measure." It follows the pattern of other scientific "-meter" instrument names such as barometer and spectrometer. The word emerged in the late nineteenth century alongside early cell-counting devices, and its usage expanded dramatically in the twentieth century with the development of flow cytometry.
Related word forms
How cytometer is actually used
A technical term confined almost entirely to laboratory medicine, immunology, and biological research. In modern usage "cytometer" nearly always implies a flow cytometer unless stated otherwise.
Easily confused with cytometer
Cytology is the study of cells; a cytometer is an instrument used to measure or count them.
A spectrometer analyzes light spectra generally, while a cytometer is specifically designed to count and characterize cells.