Nuclear Green™ Photo-Fixable DCS1 *5 mM DMSO Solution*

Ex/Em = 510/532 nm (bound to DNA)

Caution: The following protocol can be adapted for most cell types. Growth medium, cell density, the presence of other cell types, and factors may influence staining. Residual detergent on glassware may also affect the staining of many organisms and cause brightly stained material to appear in solutions with or without cells present.

1. Add 2 to 10 µM of Nuclear Green™ Photo-Fixable DCS1 to fixed, dead, or apoptotic cells (whether in suspension or adherent) and incubate for 15 to 60 minutes.

   Note: To determine the optimal concentration for the desired result, it is advisable to test a wide range of dye concentrations in initial experiments.

   Optional: Wash the cells twice with Hanks and 20 mM HEPES buffer (HBSS) or a buffer of your choice. Then, fill the wells with fresh HBSS or growth medium.

2. Observe the cells using a fluorescence microscope, fluorescence microplate reader, or flow cytometer equipped with the desired filter set. 

3. Optional: Fix cells with 4% formaldehyde for 20 minutes at room temperature. Wash cells twice to get rid of any fixation solution.

   Optional: Photofix cells with moderate UV illumination at 365 nm.