Flow Cytometry: Scattering Light to Measure Cells

Scientists analyze and quantify characteristics of cells and other particles with the power of lasers.

Written byShelby Bradford, PhD
| 2 min read

Register for free to listen to this article
Listen with Speechify
0:00
2:00
Share

A high-throughput, single-cell method enables researchers to assess several cell parameters simultaneously with the help of lasers.

Infographic showing how flow cytometry enables researchers to assess several cell parameters simultaneously at a single-cell level with the help of lasers.

(1) Sample Uptake

Scientists prepare samples as single cell suspensions and labels components of interest with fluorescent antibodies or other probes. The cytometer uses pumps to draw the sample through tubing to analyze it.

(2) Cellular Alignment

Using hydrodynamic focusing the instrument injects the sample into a fast-moving stream of fluid that funnels the sample single file through a narrow channel.

(3) Laser Interrogation

The channel leads to a point where the individual cells intersect with one or more lasers. The measured sample is deposited into a waste receptable after it passes this point.

(4) Light Scatter and Detection

As a cell begins to cross the laser beam, it scatters light. Light that mostly crosses the cell is detected as forward scatter and measures the cell’s size. Light that encounters obstacles in the cell changes direction and is detected by a side scatter detector, indicating the granularity of the cell. If the lasers excite fluorescent molecules in the cell, the emitted light is channeled through dichroic mirrors and bandpass filters to isolate specific wavelengths that meet detectors specific for those wavelengths.

Read the full story.

Related Topics

Meet the Author

  • Shelby Bradford, PhD

    Shelby is an Assistant Editor at The Scientist. She earned her PhD in immunology and microbial pathogenesis from West Virginia University, where she studied neonatal responses to vaccination. She completed an AAAS Mass Media Fellowship at StateImpact Pennsylvania, and her writing has also appeared in Massive Science. Shelby participated in the 2023 flagship ComSciCon and volunteered with science outreach programs and Carnegie Science Center during graduate school. 

    View Full Profile

Published In

The Scientist's 2024 summer issue cover
Summer 2024

Synthetic Biology is in Fashion

Scientists are pulling on the protein threads that bind textiles and cosmetics together.

Share
You might also be interested in...
Loading Next Article...
You might also be interested in...
Loading Next Article...
Illustration of a developing fetus surrounded by a clear fluid with a subtle yellow tinge, representing amniotic fluid.
January 2026

What Is the Amniotic Fluid Composed of?

The liquid world of fetal development provides a rich source of nutrition and protection tailored to meet the needs of the growing fetus.

View this Issue
Human-Relevant In Vitro Models Enable Predictive Drug Discovery

Advancing Drug Discovery with Complex Human In Vitro Models

Stemcell Technologies
Redefining Immunology Through Advanced Technologies

Redefining Immunology Through Advanced Technologies

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Ensuring Regulatory Compliance in AAV Manufacturing with Analytical Ultracentrifugation

Beckman Coulter Logo
Conceptual multicolored vector image of cancer research, depicting various biomedical approaches to cancer therapy

Maximizing Cancer Research Model Systems

bioxcell

Products

Sino Biological Logo

Sino Biological Expands Research Reagent Portfolio to Support Global Nipah Virus Vaccine and Diagnostic Development

Beckman Coulter

Beckman Coulter Life Sciences Partners with Automata to Accelerate AI-Ready Laboratory Automation

Refeyn logo

Refeyn named in the Sunday Times 100 Tech list of the UK’s fastest-growing technology companies

Parse Logo

Parse Biosciences and Graph Therapeutics Partner to Build Large Functional Immune Perturbation Atlas