What is DAPI and what does it do?

DAPI (4′,6-diamidino-2-phenylindole) is a blue-fluorescent DNA stain that exhibits ~20-fold enhancement of fluorescence upon binding to AT regions of dsDNA. DAPI is generally used to stain fixed cells since the dye is cell impermeant, although the stain will enter live cells when used at higher concentrations.

What are the excitation and emission properties of DAPI?

DAPI has an excitation peak at 350 nm and an emission peak at 465 nm, and is spectrally similar to Hoechst (33342), AlexaFluor® 350 or DyLight™ 350 DAPI is a commonly used DNA stain that binds to AT regions and has many favorable properties.

What light excites DAPI?

ultraviolet (UV) light
Normally, DAPI bound to DNA is maximally excited by ultraviolet (UV) light at 358 nm, and emits maximally in the blue range, at 461 nm. Hoechst dyes 33258 and 33342 have similar excitation and emission spectra and are also used to stain nuclei and chromosomes.

What is the absorption maximum of 4/6 Diamidino 2 Phenylindole?

DAPI is excited with ultraviolet (UV) light (maximum absorption at 358 nm) and upon binding, emits light in the blue portion of the spectrum (461 nm for DNA and ~500 nm for RNA).

How does DAPI enter the cell?

It is believed that DAPI associates with the minor groove of double-stranded DNA, with a preference for the adenine-thymine clusters. Cells must be permeabilized and/or fixed for DAPI to enter the cell and to bind DNA. Fluorescence increases approximately 20-fold when DAPI is bound to double-stranded DNA.

What is DAPI immunofluorescence?

DAPI is a classic nuclear counterstain for immunofluorescence microscopy, as well as an important component of high-content screening methods requiring cell-based quantitation of DNA content. DAPI is offered in powdered solid and aqueous solution forms.

Is DAPI cell permeable?

DAPI – a membrane-permeable fluorescent dye that intercalates with DNA to produce blue fluorescence.

Is DAPI hydrophobic or hydrophilic?

Indeed, as DAPI is hydrophobic it confers this behaviour on the DNA and thus restricts the presence of water molecules.

Why do we use DAPI?

A simple-to-use fluorescent stain, 4′,6-diamidino-2-phenylindole (DAPI), visualizes nuclear DNA in both living and fixed cells. DAPI staining was used to determine the number of nuclei and to assess gross cell morphology. DAPI staining allows multiple use of cells eliminating the need for duplicate samples.

Does DAPI only emit UV light?

Normally, DAPI bound to DNA is maximally excited by Ultraviolet (UV) light at 358 nm, and emits maximally in the blue range, at 461 nm.

Is DAPI soluble in PBS?

DAPI readily dissolves in water, but does not dissolve directly into PBS even with heat and sonication.

What does DAPI stain do?