Hoechst 33258 nucleic acid stain is a popular nuclear counterstain that emits blue fluorescence when bound to double-strand DNA. It is commonly used for counterstaining, apoptosis and cell cycle studies. Compare to Hoechst 33342, Hoechst 33258 is less cell-permeant.

Excitation Wavelength: 358nm (ultraviolet light)

Emission Wavelength: 461nm (blue/cyan fluorescence light)