for nucleic acid staining

2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride, 4′,6-Diamidino-2-phenylindole dihydrochloride, DAPI dihydrochloride
Empirical Formula (Hill Notation):
C16H15N5 · 2HCl
CAS Number:
Molecular Weight:
Beilstein/REAXYS Number:
EC Number:
MDL number:
PubChem Substance ID:


for molecular biology

Quality Level


≥98% (HPLC and TLC)




transfection: suitable


H2O: 20 mg/mL (heat or sonication may be required. Solutions stored in the dark at room temperature or 4 °C should be stable for 2 to 3 weeks.)
PBS: insoluble

ε (extinction coefficient)

30 at 263 nm in H2O at 1 mM


λex 340 nm; λem 488 nm (nur DAPI)
λex 364 nm; λem 454 nm (DAPI-DNA-Komplex)


suitable for fluorescence

storage temp.


SMILES string




InChI key


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General description

DAPI (4′,6-Diamidino-2-phenylindole dihydrochloride) is a cell permeable, fluorescent dye that binds to DNA.


Suitable for
  • DNA staining in agarose gels
  • analysis of changes in DNA during apoptosis
  • detection of mycoplasma
  • photofootprinting of DNA
  • immunofluorescent staining of cells

DAPI has been used:-
  • in rapid monitoring of microbial contamination
  • in chromosomal banding technique
  • in detection of apoptotic cells
  • in fluorescence microscopy to track the DisA (DNA integritiy scanning protein) movement on Bacillus subtilis DNA
  • to stain mature pollen grains(0.5 mg/ml)
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.


1, 5, 10, 50 mg in glass bottle

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.


Protect from light.


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. Aside from the applications described on the product page, how is D9542, 4´,6-Diamidino-2-phenylindole dihydrochloride (DAPI), used?

    DAPI is used as a nuclear counterstain in our FISH protocol at 2 μg/mL in antifade mounting media. DAPI can also be used as a vital dye to stain mature pollen grains (0.5 μg/mL). DAPI can bind to RNA, but its selectivity for DNA over RNA is high.  It appears that DAPI uses an intercalating binding mode with RNA that is AU selective (Biochem., 31, 3103 (1992)). Selectivity of DAPI for DNA over RNA is greater than that shown by ethidium bromide and propidium iodide (Nucleic Acid Research, 6, 3535 (1979))

  2. 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. 

R Howden et al.
Genetics, 149(2), 621-631 (1998-06-11)
As a strategy for the identification of T-DNA-tagged gametophytic mutants, we have used T-DNA insertional mutagenesis based on screening for distorted segregation ratios by antibiotic selection. Screening of approximately 1000 transgenic Arabidopsis families led to the isolation of eight lines...
J Kapuscinski
Biotechnic & histochemistry : official publication of the Biological Stain Commission, 70(5), 220-233 (1995-09-01)
DAPI (4',6-diamidino-2-phenylindole) is a DNA-specific probe which forms a fluorescent complex by attaching in the minor grove of A-T rich sequences of DNA. It also forms nonfluorescent intercalative complexes with double-stranded nucleic acids. The physicochemical properties of the dye and...
Yan Li et al.
Toxicology letters, 154(3), 225-233 (2004-10-27)
Excessive exposure to synthetic and endogenous estrogens has been associated with the development of cancer in several tissues including the breast. 4-Hydroxyequilenin (4-OHEN), a major catechol metabolite of equine estrogens present in Premarin, an estrogen replacement formulation, has been shown...
K Nakajima et al.
Letters in applied microbiology, 40(2), 128-132 (2005-01-13)
To apply fluorescent staining method for fast assessment of microbial quality of herbal medicines. The number of total bacteria and esterase-active bacteria on powdered traditional Chinese medicines were enumerated by fluorescent staining method using 6-carboxyfluorescein diacetate (6CFDA) and 4',6-diamidino-2-phenylindole (DAPI)...
Michal Bejerano-Sagie et al.
Cell, 125(4), 679-690 (2006-05-23)
In response to DNA damage, cells activate checkpoint signaling cascades to control cell-cycle progression and elicit DNA repair in order to maintain genomic integrity. The sensing and repair of lesions is critical for Bacillus subtilis cells entering the developmental process...
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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