Hoechst 33342, 20 mM in water

Hoechst 33342 from emp Biotech is a high-quality reagent for fixed- and live-cell fluorescent staining of DNA and cell nuclei, formulated specifically for cellular imaging techniques.  It is primarily used for specifically staining nuclei of living or fixed cells and tissues.

Hoechst 33342 (2'-[4-ethoxyphenyl]-5-[4-methyl-1-piperazinyl]-2,5'-bi-1H-benzimidazole trihydrochloride trihydrate) is excited by UV light to emit a blue fluorescence between 460 to 490nm.  It is cell-permeable and binds preferentially to adenine-thymine (A-T) regions and into the minor groove of DNA.  In addition, Hoechst 33342 exhibits distinct fluorescence emission spectra dependent on dye:base pair ratios and is also commonly used in combination with:

5-bromo-2'-deoxyuridine (BrdU) # to characterize compact chromatin of apoptic nuclei, to classify replicating cells, and to sort cells subject to their DNA content

Propidium iodide # to distinguish various stages of apoptosis and cell-cycle distribution with simultaneous flow cytometric and fluorescence imaging analysis

Hoechst 33342 Aqueous Solution is compatible with antibodies and other probes which have been labeled with fluorescein and rhodamine, and can be used in tandem as a counterstain with such probes. 

Excitation: 346 nm (361 nm with dsDNA)