Image of SYTO® 82 Orange Nucleic Acid Stain

Nuclear stain for eukaryotic and prokaryotic cells

SYTO® 82 is a cell-permeant, non-exclusive nucleic acid stain that shows a large fluorescence enhancement upon binding. In both live and dead eukaryotic cells, SYTO® 82 generally shows cytoplasmic or mitochondrial as well as nuclear staining. In addition, SYTO® 82 will stain most live and permeabilized bacteria.

This protocol can be used for:

  • Nucleic acid (nuclear) staining in fluorescence microscopy

This protocol should not be used for:

  • Flow cytometry

You will need the following for this protocol:


1. Culture cells in an appropriate medium and vessel for fluorescence microscopy.
2. Remove the medium.
3. Wash the cells 1–3 times in a phosphate-free buffer to remove the medium.
4. Prepare the SYTO® 82 staining solution by diluting the stock solution 1:1,000 (5 µM) in a phosphate-free buffer.
5. Add sufficient staining solution to cover the cells.
6. Incubate for 5–30 minutes, protected from light.
7. Remove the staining solution.
8. Wash sample 3 times in a phosphate-free buffer.
9. Image the cells.
Spectral information and storage
 SYTO® 82
Excitation/Emission (nm)541/560
Standard filter setTRITC
EVOS® Light CubeRFP
Storage conditions≤–20°C


Protocol tips

  • Warm to room temperature and briefly centrifuge the DMSO solution to the bottom of the vial each time before use.
  • Try multiple dye concentrations in the range from 100 nM to 5 µM to determine the optimal concentration.
  • In general, the best results are obtained in buffers that do not contain phosphate, such as Hank’s Balanced Salt Solution (Cat. No. 14025092).

Cells stained with SYTO® 82
Cells stained with SYTO® 82 dye and imaged with the Thermo Scientific™ CellInsight™ High-Content System.