PI Brite™

Ex/Em = 536/620 nm (bound to DNA)

PI Brite™ staining is typically conducted as a final step after all other types of staining. This staining method is used to identify only dead cells. The procedure can be adjusted to work with most cell types, but factors such as growth medium, cell density, the presence of other cell types, and other variables may affect the staining process. Additionally, any residual detergent on glassware may impact the actual or perceived staining of many organisms. This can cause brightly stained material to appear in both solutions with and without cells present.

1. Make a 1 to 10 mM PI Brite™ stock solution in high-quality DMSO.

   Note: Any unused PI Brite™ stock solution should be divided into single-use aliquots and stored at -20 °C, protected from light. Avoid repeated freeze-thaw cycles.

2. Use the fixation protocol appropriate for your sample.

3. Pellet cells by centrifugation and resuspend the cells in buffered salt solutions or media, with optimal dye staining at pH 7.4. Adherent cells in culture may be stained in situ on coverslips or in the cell culture wells. 

4. Add PI Brite™ using the concentrations between 0.5 and 5 µM and incubate it for 15 to 60 minutes as a guide.

   Note: In initial experiments, it may be best to try several dye concentrations over the entire suggested range to determine the concentration that yields optimal staining.