DAPI, blue fluorescent nucleic acid stain

Nuclei Cell viability and apoptosis Microscopy Flow cytometry
Cat. # Quantity Price Lead time
2996-1mL 1 mL, 1 mg/mL in Water $75 in stock
2996-50uL 50 uL, 1 mg/mL in Water –   in stock
2996-1mg 1 mg $30 in stock
2996-10mg 10 mg $110 in stock
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DAPI (4′,6-diamidino-2-phenylindole) is a blue-emitting fluorescent dye that binds strongly to adenine-thymine-rich regions in DNA. It is used extensively in fluorescence microscopy, flow cytometry for chromosome staining and as a nuclear counterstain. DAPI is generally used to stain fixed cells since the dye is membrane impermeant, although the dye can enter live cells when used at high concentrations.

When bound to double-stranded DNA, DAPI exhibits ~20-fold enhancement of fluorescence with an absorption maximum at 355 nm and emission maximum at 460 nm. DAPI also binds to RNA, though it is not as strongly fluorescent. When bound to RNA, its emission spectrum shifts to around 500 nm.

There is a slight fluorescence overlap between DAPI and green-fluorescent molecules like fluorescein and GFP. Use spectral unmixing if extremely precise image analysis is required.

DAPI is several times more sensitive than ethidium bromide for staining DNA in agarose gels. It may be used for photofootprinting DNA and detecting annealed probes in blotting applications by specifically visualizing the double-stranded complex. Also, DAPI staining is a sensitive and specific detection method for mycoplasma.

DAPI, blue fluorescent nucleic acid stain, 2996-10mg
DAPI, blue fluorescent nucleic acid stain, 2996-10mg
Human blood smear stained with blue fluorescent nuclear stain DAPI and antibodies to neutrophil myeloperoxidase. Human blood smear stained with blue fluorescent nuclear stain DAPI (2996-x) and antibodies to neutrophil myeloperoxidase. Antibodies were labeled with red fluorescent dye sulfo-Cyanine5 using the Lumiprobe sulfo-Cyanine5 antibody labeling kit (3321-x).
Structure of DAPI
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Absorption and emission spectra of DAPI

Absorption and emission spectra of DAPI

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General properties

Appearance: yellow solid / solution
Molecular weight: 350.25
CAS number: 28718-90-3
Molecular formula: C16H17Cl2N5
Solubility: good in DMF, DMSO
Quality control: NMR 1H and HPLC-MS (95+%)
Storage conditions: 24 months after receival at -20°C in the dark. Transportation: at room temperature for up to 3 weeks. Desiccate.
MSDS: Download
Product specifications

Spectral properties

Excitation/absorption maximum, nm: 355
ε, L⋅mol−1⋅cm−1: 28800
Emission maximum, nm: 460

Product citations

  1. Potapenko, E.Y..; Kashko, N.D.; Knorre, D.A. Spontaneous Mutations in Saccharomyces cerevisiae mtDNA Increase Cell-to-Cell Variation in mtDNA Amount. International Journal of Molecular Sciences, 2023, 24(24), 17413. doi: 10.3390/ijms242417413
This Product is offered and sold for research purposes only. It has not been tested for safety and efficacy in food, drug, medical device, cosmetic, commercial or any other use. Supply does not express or imply authorization to use for any other purpose, including, without limitation, in vitro diagnostic purposes, in the manufacture of food or pharmaceutical products, in medical devices or in cosmetic products.
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