4′,6-Diamidino-2-phenylindole dihydrochloride

BioReagent, suitable for fluorescence, ≥95.0% (HPLC)

2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride, DAPI dihydrochloride
Empirical Formula (Hill Notation):
C16H15N5 · 2HCl
CAS Number:
Molecular Weight:
Beilstein/REAXYS Number:
EC Number:
MDL number:
PubChem Substance ID:
Pricing and availability is not currently available.

Quality Level

product line



≥95.0% (HPLC)


DMF: soluble
H2O: soluble


λex 340 nm; λem 488 nm (nur DAPI)
λex 364 nm; λem 454 nm (DAPI-DNA-Komplex)
λex 374 nm; λem 461 nm in 10 mM Tris; 1 mM EDTA; pH 8.0; DNA


suitable for fluorescence

SMILES string




InChI key


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DAPI is several times more sensitive than ethidium bromide for staining DNA in agarose gels. It may be used for photofootprinting of DNA, to detect annealed probes in blotting applications by specifically visualizing the double-stranded complex, and to study the changes in DNA and analyze DNA content during apoptosis using flow cytometry. DAPI staining has also been shown to be a sensitive and specific detection method for mycoplasma.

Biochem/physiol Actions

Cell permeable fluorescent minor groove-binding probe for DNA. Binds to the minor groove of double-stranded DNA (preferentially to AT rich DNA), forming a stable complex which fluoresces approximately 20 times greater than DAPI alone.


Bottomless glass bottle. Contents are inside inserted fused cone.


Exclamation mark

Signal Word


Hazard Statements

Target Organs

Respiratory system

Personal Protective Equipment

dust mask type N95 (US),Eyeshields,Gloves


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 can I make a solution of 4´,6-Diamidino-2-phenylindole dihydrochloride (DAPI), Product 32670?

    DAPI is soluble in water (10 mg/mL) with heat or sonication as necessary. It is insoluble in PBS even at 1 mg/ml.

  4. How can I store solutions of 4´,6-Diamidino-2-phenylindole dihydrochloride (DAPI), Product 32670?

    At 1 mg/mL, the solutions are stable in the dark at 2-8 °C for several weeks. For long-term storage, the solutions can be divided into aliquots and stored frozen at -20°C

  5. What concentration of 4´,6-Diamidino-2-phenylindole dihydrochloride (DAPI), Product 32670, is used to as a nuclear counterstain for tissue sections?

    Following fluorescent staining of the cells, DAPI is added to the mounting media at 2 μg/ml.

  6. What concentration of 4´,6-Diamidino-2-phenylindole dihydrochloride (DAPI), Product 32670, is used to as a nuclear stain for cultured cells?

    Use DAPI at 0.1 microgram per mL in phosphate buffered saline (PBS) to incubate with monolayer cultured cells for 15-30 minutes at 30°C.  Immediately examine with a fluorescence microscope.

  7. 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.

  8. 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. 

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

    Ask a Scientist here.

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

    Ask a Scientist here.

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