bisBenzimide H 33342 trihydrochloride

≥98% (HPLC and TLC)

Hoechst 33342, HOE 33342, bisBenzimide, 2′-(4-Ethoxyphenyl)-5-(4-methyl-1-piperazinyl)-2,5′-bi-1H-benzimidazole trihydrochloride
Empirical Formula (Hill Notation):
C27H28N6O · 3HCl · xH2O
CAS Number:
Molecular Weight:
561.93 (anhydrous basis)
Beilstein/REAXYS Number:
MDL number:
PubChem Substance ID:

Quality Level


≥98% (HPLC and TLC)




hematology: suitable
histology: suitable


1.7 (20 °C)


H2O: 20 mg/mL
phosphate buffer: precipitates


suitable for fluorescence

Featured Industry

Diagnostic Assay Manufacturing

storage temp.


SMILES string




InChI key


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Bisbenzimide Hoechst 33342 is a specific stain for AT-rich regions of double-stranded DNA and has been shown to displace several known DNA intercalators. This fluorescent dye has been used in sorting living cells based on DNA content, used in flow cytometry for the determination of DNA content, and for the visualization of chromatin distribution in living cells. It has been used to detect BrdU incorporation into cells and in studying the initial stages apoptosis and cellcycle distribution., Chromosomes that are dividing or replicating will not stain with this dye.
Useful for staining DNA, chromosomes and nuclei. May be used for fluorescence microscopy or flow cytometry.
Excitation max. = 346 nm
Emission max. = 460 nm


25 mg in poly bottle
1 g in glass bottle
100, 500 mg in glass bottle

Biochem/physiol Actions

Membrane-permeable, fluorescent DNA stains with low cytotoxicity that intercalate in A-T regions of DNA.

Physical properties

Fluorescent properties of bisBenzimide H 33342:
Free dye: Excitation maximum = 340 nm, Emission maximum = 510 nm (5 mM HEPES, 10 mM NaCl, pH 7.0) DNA complex: Excitation maximum = 355 nm, Emission maximum = 465 nm (5 mM HEPES, 10 mM NaCl, pH 7.0)

Preparation Note

This product is soluble in water (50 mg/ml), yielding a clear solution. The pH of a 2% solution is 1.9. It has been observed that this material will precipitate from phosphate buffer solutions.
Aqueous solutions are stable for 1 month if kept in the dark at 2-8 °C.


NONH for all modes of transport

WGK Germany


Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Certificate of Analysis

Certificate of Origin

  1. Which document(s) contains shelf-life or expiration date information for a given product?

    If available for a given product, the recommended re-test date or the expiration date can be found on the Certificate of Analysis.

  2. How do I get lot-specific information or a Certificate of Analysis?

    The lot specific COA document can be found by entering the lot number above under the "Documents" section.

  3. How do I find price and availability?

    There are several ways to find pricing and availability for our products. Once you log onto our website, you will find the price and availability displayed on the product detail page. You can contact any of our Customer Sales and Service offices to receive a quote.  USA customers:  1-800-325-3010 or view local office numbers.

  4. What is the Department of Transportation shipping information for this product?

    Transportation information can be found in Section 14 of the product's (M)SDS.To access the shipping information for this material, use the link on the product detail page for the product. 

  5. What is a typical concentration of Product B2261, bisBenzimide H 33342 trihydrochloride, for staining DNA in cells?

    200 micrograms per mL.

  6. Can solvents other than water be used to dissolve Product B2261, bisBenzimide H 33342 trihydrochloride?

    Hoechst 33342 can be dissolved in N,N-dimethylformamide (DMF).

  7. Which Hoechst dye is suitable for chromosomal analysis?

    Hoechst 33258 (Product No. B2883) is the preferred Hoechst dye for chromosomal analysis. Hoechst 33342 (Product No. B2261) is a poor fluorochrome for chromosomal analysis.

  8. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

  9. My question is not addressed here, how can I contact Technical Service for assistance?

    Ask a Scientist here.

P E Mozdziak et al.
Cytometry, 41(2), 89-95 (2000-09-26)
5-Bromo-2'-deoxyuridine (BrdU) is a powerful compound to study the mitotic activity of a cell. Most techniques that identify BrdU-labeled cells require conditions that kill the cells. However, the fluorescence intensity of the membrane-permeable Hoechst dyes is reduced by the incorporation...
Basic helix-loop-helix transcriptional factor MyoR regulates BMP-7 in acute kidney injury.
Kamiura N, et al.
American Journal of Physiology: Renal Physiology, 304, F1159-F1166 (2013)
D J Arndt-Jovin et al.
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society, 25(7), 585-589 (1977-07-01)
The methods for measuring the deoxyribonucleic acid content of individual mammalian cells and sorting them on the basis of this parameter have until now required fixation or other treatment which renders the cells nonviable. Using a class of bis-benzimidazole dyes...
M G Ormerod et al.
Cytometry, 14(6), 595-602 (1993-01-01)
We have recently developed a method for the separation and quantification of viable apoptotic cells without the need for permeabilisation or fixation of the cells. The method is based on the observation that apoptotic rat thymocytes fluoresce more brightly than...
M Gregoire et al.
Experimental cell research, 152(1), 38-46 (1984-05-01)
Chromatin distribution was visualized in living cells with the selective DNA fluorochrome Hoechst 33342. This dye was shown to be non-toxic on the rat kangaroo PTO cell line by measuring the labelled cell growth rate. The aim of this work...
Regulation of the cell cycle involves processes crucial to the survival of a cell, including the detection and repair of genetic damage as well as the prevention of uncontrolled cell division associated with cancer. The cell cycle is a four-stage process in which the cell 1) increases in size (G1-stage), 2) copies its DNA (synthesis, S-stage), 3) prepares to divide (G2-stage), and 4) divides (mitosis, M-stage). Due to their anionic nature, nucleoside triphosphates (NTPs), the building blocks of both RNA and DNA, do not permeate cell membranes.
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