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Hoechst 33342 *20 mM solution in water*

Chemical structure for Hoechst 33342 *20 mM solution in water*
Chemical structure for Hoechst 33342 *20 mM solution in water*
HeLa cells were incubated in 1X HBSS buffer with 5% serum to induce starvation. Following starvation, cells were treated with Autophagy Green™ (Cat No. 23002) working solution for 20 minutes in a 37°C, 5% CO<sub>2</sub> incubator and then washed 3 times. Nuclei were labeled with Hoechst 33342 (Cat No. 17530). Lysosomes were labeled with LysoBrite™ Orange (Cat No. 22657).
Ordering information
Price ()
Catalog Number17535
Unit Size
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Additional ordering information
InternationalSee distributors
ShippingStandard overnight for United States, inquire for international
Physical properties
Molecular weight561.93
Spectral properties
Excitation (nm)352
Emission (nm)454
Storage, safety and handling
H-phraseH303, H313, H340
Hazard symbolT
Intended useResearch Use Only (RUO)
R-phraseR20, R21, R68
StorageFreeze (< -15 °C); Minimize light exposure


Molecular weight
Excitation (nm)
Emission (nm)
The Hoechst stains are a family of fluorescent stains for labeling DNA in fluorescence microscopy. Because these fluorescent stains label DNA, they are also commonly used to visualize nuclei and mitochondria. Two of these closely related bis-benzimides are commonly used: Hoechst 33258 and Hoechst 33342. Both dyes are excited by ultraviolet light at around 350 nm, and both emit blue/cyan fluorescence light around an emission maximum at 461 nm. The Hoechst stains may be used on live or fixed cells, and are often used as a substitute for another nucleic acid stain, DAPI. The key difference between them is that the additional ethyl group of Hoechst 33342 renders it more lipophilic, and thus more able to cross intact cell membranes. In some applications, Hoechst 33258 is significantly less permeant. These dyes can also be used to detect the contents of a sample DNA by plotting a standard emission-to-content curve.


Fluorescence microscope

Excitation350 nm
Emission461 nm
Recommended plateBlack wall/clear bottom


Common stock solution preparation

Table 1. Volume of Water needed to reconstitute specific mass of Hoechst 33342 *20 mM solution in water* to given concentration. Note that volume is only for preparing stock solution. Refer to sample experimental protocol for appropriate experimental/physiological buffers.

0.1 mg0.5 mg1 mg5 mg10 mg
1 mM177.958 µL889.791 µL1.78 mL8.898 mL17.796 mL
5 mM35.592 µL177.958 µL355.916 µL1.78 mL3.559 mL
10 mM17.796 µL88.979 µL177.958 µL889.791 µL1.78 mL

Molarity calculator

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Spectral properties

Excitation (nm)352
Emission (nm)454

Product family

NameExcitation (nm)Emission (nm)Extinction coefficient (cm -1 M -1)Quantum yield
Hoechst 33258 *CAS 23491-45-4*3524544600010.03401
Hoechst 33258 *20 mM solution in water*3524544600010.03401
Hoechst 34580 *CAS 911004-45-0*371438--
Hoechst 34580 *20 mM solution in water*371438--


View all 11 citations: Citation Explorer
NAMPT Inhibitor and P73 Activator Represses P53 R175H Mutated HNSCC Cell Proliferation in a Synergistic Manner
Authors: Cai, Bi-He and Bai, Zhi-Yu and Lien, Ching-Feng and Yu, Si-Jie and Lu, Rui-Yu and Wu, Ming-Han and Wu, Wei-Chen and Chen, Chia-Chi and Hsu, Yi-Chiang
Journal: Biomolecules (2022): 438
Thoroughly remold the localization and signaling pathway of TLR22
Authors: Ji, Jianfei and Liao, Zhiwei and Rao, Youliang and Li, Wenqian and Yang, Chunrong and Yuan, Gailing and Feng, Hao and Xu, Zhen and Shao, Jianzhong and Su, Jianguo
Journal: Frontiers in immunology (2020): 3003
Plant-derived alkaloid sinomenine potentiates glucocorticoid pharmacodynamics in mitogen-activated human peripheral blood mononuclear cells by regulating the translocation of glucocorticoid receptor
Authors: Xu, Wencheng and Wang, Xiaoqin and Tu, Yuanchao and Masaki, Hiroshi and Tanaka, Sachiko and Onda, Kenji and Sugiyama, Kentaro and Yamada, Haruki and Hirano, Toshihiko
Journal: Phytotherapy research (2019): 187--196
Tetrandrine and cepharanthine induce apoptosis through caspase cascade regulation, cell cycle arrest, MAPK activation and PI3K/Akt/mTOR signal modification in glucocorticoid resistant human leukemia Jurkat T cells
Authors: Xu, Wencheng and Wang, Xiaoqin and Tu, Yuanchao and Masaki, Hiroshi and Tanaka, Sachiko and Onda, Kenji and Sugiyama, Kentaro and Yamada, Haruki and Hirano, Toshihiko
Journal: Chemico-Biological Interactions (2019): 108726
Helicobacter pylori cholesterol glucosylation modulates autophagy for increasing intracellular survival in macrophages
Authors: Lai, Chih-Ho and Huang, Ju-Chun and Cheng, Hsin-Hung and Wu, Meng-Chen and Huang, Mei-Zi and Hsu, Hui-Ying and Chen, Yu-An and Hsu, Chung-Yao and Pan, Yi-Jiun and Chu, Yen-Ting and others, undefined
Journal: Cellular microbiology (2018): e12947
DOTA Functionalized Cross-Linked Small-Molecule Micelles for Theranostics Combining Magnetic Resonance Imaging and Chemotherapy
Authors: Feng, Jianyue and Luo, Qiang and Chen, Yun and Li, Bing and Luo, Kui and Lan, Jingbo and Yu, Yunlong and Zhang, Shiyong
Journal: Bioconjugate chemistry (2018)
MDA5 Induces a Stronger Interferon Response than RIG-I to GCRV Infection through a Mechanism Involving the Phosphorylation and Dimerization of IRF3 and IRF7 in CIK Cells
Authors: Wan, Quanyuan and Yang, Chunrong and Rao, Youliang and Liao, Zhiwei and Su, Jianguo
Journal: Frontiers in Immunology (2017)
Grafting of Ring-Opened Cyclopropylamine thin films on Silicon (100) Hydride via UV Photoionization
Authors: Tung, Joline and Ching, Jing Yuan and Ng, Yoke Mooi and Tew, Lih Shin and Khung, Yit Lung
Journal: ACS Applied Materials & Interfaces (2017)
Dual-functionalized graphene oxide for enhanced siRNA delivery to breast cancer cells
Authors: Imani, Rana and Shao, Wei and Taherkhani, Samira and Emami, Shahriar Hojjati and Prakash, Satya and Faghihi, Shahab
Journal: Colloids and Surfaces B: Biointerfaces (2016): 315--325


View all 42 references: Citation Explorer
Usefulness of a triple fluorochrome combination Merocyanine 540/Yo-Pro 1/Hoechst 33342 in assessing membrane stability of viable frozen-thawed spermatozoa from Estonian Holstein AI bulls
Authors: Hallap T, Nagy S, Jaakma U, Johannisson A, Rodriguez-Martinez H.
Journal: Theriogenology (2006): 1122
Fatty acid synthase and its mRNA concentrations are decreased at different times following Hoechst 33342-induced apoptosis in BC3H-1 myocytes
Authors: Zhang X, Kiechle FL.
Journal: Ann Clin Lab Sci (2006): 185
The DNA minor groove binding agents Hoechst 33258 and 33342 enhance recombinant adeno-associated virus (rAAV) transgene expression
Authors: Li L, Yang L, Kotin RM.
Journal: J Gene Med (2005): 420
Resistance mechanism development to the topoisomerase-I inhibitor Hoechst 33342 by Leishmania donovani
Authors: Marquis JF, Hardy I, Olivier M.
Journal: Parasitology (2005): 197
Acid-base and electronic structure-dependent properties of Hoechst 33342
Authors: Aleman C, Namba AM, Casanovas J.
Journal: J Biomol Struct Dyn (2005): 29
Single UV excitation of Hoechst 33342 and propidium iodide for viability assessment of rhesus monkey spermatozoa using flow cytometry
Authors: Cai K, Yang J, Guan M, Ji W, Li Y, Rens W.
Journal: Arch Androl (2005): 371
Evidence for a qualitative hierarchy within the Hoechst-33342 'side population' (SP) of murine bone marrow cells
Authors: Robinson SN, Seina SM, Gohr JC, Kuszynski CA, Sharp JG.
Journal: Bone Marrow Transplant (2005): 807
Flow cytometric characterization of viable meiotic and postmeiotic cells by Hoechst 33342 in mouse spermatogenesis
Authors: Bastos H, Lassalle B, Chicheportiche A, Riou L, Testart J, Allem and I, Fouchet P.
Journal: Cytometry A (2005): 40
An in vitro study of Hoechst 33342 redistribution and its effects on cell viability
Authors: Mohorko N, Kregar-Velikonja N, Repovs G, Gorensek M, Bresjanac M.
Journal: Hum Exp Toxicol (2005): 573
Role of topoisomerases in cytotoxicity induced by DNA ligand Hoechst-33342 and UV-C in a glioma cell line
Authors: Singh S, Dwarakanath BS, Lazar Mathew T.
Journal: Indian J Exp Biol (2005): 313