SYTOX Dead Cell Stains Protocol | Thermo Fisher Scientific

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Membrane integrity-based cell viability assay

The SYTOX Dead Cell Stains are nucleic acid stains for assessing cell viability with flow cytometry. Dead cells have bright fluorescence and live cells have dim fluorescence. SYTOX Dead Cell Stains are available in five different colors.

This protocol can be used for:

Identifying live and dead cells using a flow cytometer

This protocol should not be used for:

Fluorescence microscopy

You will need the following for this protocol:

Cells growing in culture
One of the SYTOX Dead Cell Stains (e.g., SYTOX Green Dead Cell Stain (Cat. No. S34860))
Flow cytometer

Protocol

1. Thaw vial of dye

2. Add 1 mL cells to a flow cytometer tube

3. Add 1 µL dye to cells and mix well

4. Incubate for 15 minutes

5. Run cells on a flow cytometer

Protocol tips

Cell concentration should be 5 x 10⁷ cells per mL
No washing is required after staining
Not compatible with fixation
Dye stock solutions should be stored frozen

Spectral information and storage

	Blue	Green	Orange	AADvanced	Red
Excitation/Emission	444/480 nm	488/525 nm	547/570 nm	546/647 nm	640/658 nm
Flow cytometer channel	DAPI	FITC	PE	PerCP	Alexa Fluor 647
Storage conditions	–20°C	–20°C	–20°C	–20°C	–20°C
Cat. No.	S34857	S34860	S34861	S10349	S34859
The SYTOX Dead Cell Stain Sampler Kit (Cat. No. S34862) contains trial-sized samples of 5 different stains (50 tests per stain) to help researchers identify the best stain for their multicolor experiments.

5-panel graph showing cell viability of Jurkat cells labeled with each of the SYTOX Dead Cell stains

A mixture of heat-killed and live Jurkat cells were labeled with the SYTOX Dead Cell stains. All stains were labeled according to the listed protocol. Samples were analyzed on a flow cytometer equipped with a 488 nm laser, a 405 nm laser, or a 633 nm laser, and fluorescence emissions were collected using the appropriate filters.