Hoechst 33342 trihydrochloride (CAS 23491-52-3)

Hoechst 33342 trihydrochloride is a fluorochrome widely used to visualize cellular DNA, providing valuable insights into its structure and function. This A:T-specific DNA minor groove ligand serves multiple purposes in research. It facilitates the identification and quantification of cellular components like proteins and lipids. Moreover, it finds utility in drug delivery applications, enabling targeted delivery to specific cells or tissues. Excitation of the dye occurs at approximately 350 nm, with an emission maximum around 461 nm. Compared to other Hoechst dyes, Hoechst-33342 possesses enhanced lipophilicity due to an additional ethyl group. It displaces several known DNA intercalators and can disrupt DNA dye uptake in conjunction with Adriamycin (sc-200923). This compound is utilized for various purposes, including sorting living cells based on DNA content using FACS, visualizing chromatin distribution in live cells, detecting BrdU incorporation, and examining fixed cells under microscopy. Additionally, it plays a role in studying early apoptosis stages and cell-cycle distribution. Notably, Hoechst-33342 exhibits diverse effects on different cell types. It induces cell differentiation, binds reversibly to Friend erythroleukemia cells, inhibits Topo I (topoisomerase I), induces apoptosis in HL-60 cells, regulates Ca2+ efflux, and influences cell differentiation in junctional sarcoplasmic reticulum cells. Hoechst 33342 trihydrochloride interacts with DNA through non-covalent binding, forming a fluorescent complex. The dye specifically binds to the minor groove of double-stranded DNA, causing fluorescence quenching upon binding. Although it can bind to both single- and double-stranded DNA, its affinity is higher for the latter. While Hoechst 33342 can also bind to RNA, its binding affinity for RNA is lower compared to DNA.