Dyeexclusiontester

Dyeexclusiontester is a term used to describe a laboratory tool, device, or software package designed to perform dye exclusion viability testing on cells or microorganisms. It encompasses methods that determine whether cells retain their membrane integrity by assessing dye uptake, providing a quantitative viability readout.

The underlying principle of dye exclusion testing relies on membrane integrity. Viable cells possess intact membranes that exclude certain dyes, while non-viable cells with compromised membranes take up the dye and appear stained. Common approaches include manual counting with trypan blue on a hemocytometer and automated systems that use image analysis or flow cytometry with dyes such as propidium iodide or 7-AAD. A dye exclusion tester may integrate staining, incubation, and analysis steps into a single workflow.

Typical implementations of a dye exclusion tester include manual, semi-automated, and fully automated configurations. Features may include standardized staining protocols, automated image capture or flow-based reading, threshold-based color or fluorescence analysis, sample tracking, and data export for quality control and record-keeping. Such systems are used to generate objective viability metrics quickly, aiding decisions in cell culture, cytotoxicity testing, and microbiology.

Applications span routine culture quality control, cytotoxicity assays, stem cell and primary cell viability assessments, and high-throughput screening where rapid viability readouts are valuable. While dye exclusion methods are simple and cost-effective, limitations include dye toxicity, potential underestimation of viability in clumped cells, and dependence on proper staining conditions. Alternatives include metabolic assays and flow cytometry-based viability tests.

See also: trypan blue exclusion, viability assay, flow cytometry viability, hemocytometer.