Hoechst 33342 trihydrochloride (CAS 23491-52-3)

Hoechst-33342·3HCl (Bisbenzimide) is an AT-specific DNA minor groove ligand that is a widely used fluorochrome for visualizing cellular DNA. Excitation of the dye occurs around 350nm with an emission maxima around 461nm. Hoechst-33342 unlike other Hoechst dyes is more lipophillic due to an additional ethyl group. The compound has been observed to displace several known DNA intercalators yet the dye uptake is interfered with Adriamycin (sc-200923).

The compound can be used in sorting living cells based on DNA content by FACS, in the visualization of chromatin distribution in living cells, to detect BrdU incorporation into cells, visualization of fixed cells by microscopy, to study the initial stages of apoptosis and cell-cycle distribution. In addition to Hoechst-33342’s fluorescent capability the chemical has also had varying effects on differing cell types. The stain has been shown to induce cell differentiation, bind reversibly to Friend erythroleukemia cells, inhibit Topo I (topoisomerase I) and induce apoptosis in HL-60 cells, and in junctional sarcoplasmic reticulum cells regulated Ca²⁺ efflux and affected cell differentiation.