DAPI

WikiDoc Resources for DAPI
Articles
Most recent articles on DAPI Most cited articles on DAPI Review articles on DAPI Articles on DAPI in N Eng J Med, Lancet, BMJ
Media
Powerpoint slides on DAPI Images of DAPI Photos of DAPI Podcasts & MP3s on DAPI Videos on DAPI
Evidence Based Medicine
Cochrane Collaboration on DAPI Bandolier on DAPI TRIP on DAPI
Clinical Trials
Ongoing Trials on DAPI at Clinical Trials.gov Trial results on DAPI Clinical Trials on DAPI at Google
Guidelines / Policies / Govt
US National Guidelines Clearinghouse on DAPI NICE Guidance on DAPI NHS PRODIGY Guidance FDA on DAPI CDC on DAPI
Books
Books on DAPI
News
DAPI in the news Be alerted to news on DAPI News trends on DAPI
Commentary
Blogs on DAPI
Definitions
Definitions of DAPI
Patient Resources / Community
Patient resources on DAPI Discussion groups on DAPI Patient Handouts on DAPI Directions to Hospitals Treating DAPI Risk calculators and risk factors for DAPI
Healthcare Provider Resources
Symptoms of DAPI Causes & Risk Factors for DAPI Diagnostic studies for DAPI Treatment of DAPI
Continuing Medical Education (CME)
CME Programs on DAPI
International
DAPI en Espanol DAPI en Francais
Business
DAPI in the Marketplace Patents on DAPI
Experimental / Informatics
List of terms related to DAPI

DAPI or 4',6-diamidino-2-phenylindole is a fluorescent stain that binds strongly to DNA. It is used extensively in fluorescence microscopy. Since DAPI will pass through an intact cell membrane, it may be used to stain both live and fixed cells.

For fluorescence microscopy, DAPI is excited with ultraviolet light. When bound to double-stranded DNA its absorption maximum is at 358 nm and its emission maximum is at 461 nm. (This emission is fairly broad, and appears blue/cyan.)[1] DAPI will also bind to RNA, though it is not as strongly fluorescent. Its emission shifts to around 500 nm when bound to RNA.[2]

DAPI (magenta) bound to the minor groove of DNA (green and blue). From PDB: 1D30​.

DAPI's blue emission is convenient for microscopists who wish to use multiple fluorescent stains in a single sample. There is fluorescence overlap between DAPI and green-fluorescent molecules like fluorescein and green fluorescent protein (GFP), or red-fluorescent stains like Texas Red, but using spectral unmixing or taking images sequentially can get around this.

Apart from labelling cell nuclei, the most popular application of DAPI is in detection of mycoplasma or virus DNA in cell cultures.

Because DAPI readily enters live cells and binds tightly to DNA, it is toxic and mutagenic. Care should be taken in its handling and disposal.

The Hoechst stains are similar to DAPI in that they are also blue-fluorescent DNA stains which are compatible with both live- and fixed-cell applications.