Flow Cytometry in Clinical Diagnostics

Flow cytometer for cell analysis in a clinical laboratory

Flow cytometry is a method for analyzing the physical and chemical characteristics of individual cells or particles in a fluid stream. Cells pass through a laser beam one at a time, while detectors record scattered light and fluorescence. It is the basis of immunophenotyping, diagnosis of hematologic malignancies, immune status assessment and cell therapy.

How the Method Works

A cell suspension in a special buffer is fed into a flow cell, where hydrodynamic focusing lines the cells up in single file. Each cell crosses one or more laser beams, and the system measures several parameters simultaneously.

Main measured signals:

Forward scatter (FSC): proportional to cell size
Side scatter (SSC): reflects granularity and internal structure
Fluorescence: the signal from fluorochrome-labeled antibodies against surface and intracellular markers

Combining several fluorescence channels makes it possible to detect many markers on a single cell at the same time. This is what multiparameter immunophenotyping means.

Clinical Applications

Area	Task
Hematology / hematologic oncology	Diagnosis and monitoring of leukemias and lymphomas
Immunology	Lymphocyte subset counts (CD4/CD8)
Transplantation	Immune status assessment
Cell therapy	Quality control of CAR-T and stem cells
HIV monitoring	Measuring CD4 lymphocyte levels

Immunophenotyping by CD markers is a key tool for the differential diagnosis of hematologic malignancies and the assessment of minimal residual disease (MRD).

What to Consider When Choosing a Cytometer

The number of lasers and detectors determines how many markers can be analyzed simultaneously
Sensitivity and resolution of the fluorescence channels
Throughput: the number of events processed per second
Data analysis software and spillover (spectral overlap) compensation
Availability of quality control protocols and calibration beads

Frequently Asked Questions

How does flow cytometry differ from microscopy?

Microscopy analyzes cells visually and one at a time, while flow cytometry measures thousands of cells per second quantitatively across many parameters simultaneously.

What is immunophenotyping?

It is the identification of a cell's set of surface and intracellular markers using fluorescently labeled antibodies, which makes it possible to classify cell populations.

Can cells be sorted?

Dedicated sorters (FACS) not only analyze cells but also physically separate them according to defined characteristics for further study.

Choosing a Flow Cytometer

KombiMED GmbH is an independent partner for procurement and market access for laboratory equipment from Europe. We will help you choose a flow cytometer suited to your laboratory's needs and take care of delivery, commissioning and staff training.

See also:

Analytical Methods in Clinical Chemistry: an overview
Immunoassays: ELISA, CLIA and ligand-binding methods
Flow cytometers: catalog
Contact KombiMED for help selecting equipment