Hoechst dyes are cell membrane-permeant, minor groove-binding blue fluorescent DNA stains. Hoechst dyes are widely used in cell cycle and apoptosis studies and also as nuclear counterstains. Biotium also offers Hoechst 33258, 10 mg/ml in dH2O (#40044). Hoechst 33258 and Hoechst 33342 are spectrally similar. Hoechst 33528 is slightly more water soluble than Hoechst 33342, but both dyes are widely used in cell cycle and apoptosis studies and also as nuclear counterstains. They are typically used to stain live or fixed cells in buffer or medium at 1 ug/mL, with no wash step required.    &lamba;Ex/&lamba;Em (with DNA) = 352/461 nm  Pale yellow solid soluble in water up to 2% (w/v)  Store at -20°C and protect from light  C25H27Cl3N6O.5H2O  MW: 623.96