4 ,6-diamidino-2-phenylindole DAPI

Fig.8.1a-d. Evans blue extravasation 6 h after permanent middle cerebral artery occlusion (MCAO) in Sprague-Dawley rats. Evans blue extravasation is shown in red and cell nuclei in blue labeled by 4 -6-diamidino-2-phenylindole (DAPI), a compound that binds to DNA. (a) A low-magnification view of the entire ischemic area, (b) Evans blue extravasation from a vessel located in the area adjacent to the ischemic area, (c) Electronic magnification of the box in (b) (arrow is pointing at a leakage of Evans blue from the vessel), (d) No extravasation of Evans blue is seen in a vessel from the same section seen in (b) and (c) but located in the corresponding region of the contralateral hemisphere Contra, contralateral. [Reproduced with permission from Yepes et al. (2003)]... 

Figure 14.2 shows fluorescence intensity quenching of 4,6-diamidino-2-phenylindole (DAPI) complexed to DNA in the presence of two concentrations of Acridine Orange. In fact, one can see that while the fluorescence intensity of DAPI decreases, that of Acridine... 

ProLong Gold antifade reagent with 4 ,6-diamidino-2-phenylindole DAPI (Invitrogen, cat P36931)... 

Chloro-7-nitrobenzo[(3t]-2, 1,3-oxadiazole Dansylchloride 4, 6-Diamidino-2-phenylindole (DAPI)... 

Lower nucleic acid concentrations are best determined fluorimetrically. These methods generally depend on the fact that certain dyes can bind to nucleic acids by intercalating between successive base pairs, and this binding is accompanied by marked increases in the fluorescence quantum yield. Ethidium bromide fluorescence (Aex 260-360 nm Af.rr] 560 nm), which is commonly used to visualise nucleic acids in gel electrophoresis, can also be used to quantitate double stranded DNA and RNA with a sensitivity of about 10 ng (Karsten and Wollenberger 1977). The dye 4,6-diamidino-2-phenylindole (DAPI) (Aex 360 nm 2f.m 450 nm) can be used to quantitate DNA specifically with a detection limit of about lng (Brunk et al. 1979). 

Sensitive fluorometric assays for double-stranded (native) DNA in tissue extracts are based on the noncovalent interaction of intercalating dyes (Fig. 1.7 such as ethi-dium bromide, 4,6 -diamidino-2-phenylindole (DAPI), or 2-(2-[4-hydroxyphenyl]-6-benzimidazolyl)-6- (1-methyl-4-piperazyl)benzimidazol trihydrochloride (Hoechst 33258), with double-stranded DNA in neutral, aqueous solutions. 

An interesting label-free ECL sensor for DNA detection was developed by using DNA-binding intercalators as co-reactants. Doxorubicin, dauno-rubicin, and 4, 6-diamidino-2-phenylindole (DAPI) (Fig. 7) were recently investigated as good co-reactants for Ru(bpy)3 " " ECL. Usually, the coreactants selectively intercalate with dsDNA, showing favorable ECL with... 

Separation of mtDNA from nuclear DNA is achieved through gradients of CsCl mixed with a dye, generally ethidium bromide (EB), rarely 4 ,6-diamidino-2-phenylindole (DAPI) or propidium iodine (PDI). 

DNA by intercalation, and 4, 6-diamidino-2-phenylindole (DAPI) binds into the minor groove of DNA. Fluorescence is most enhanced when adjacent to adenine-thymine-rich regions of DNA. These labels are used to image DNA on agarose gels using a UV transilluminator for molecular biological applications. 

Figure 8.9 Confocal fluorescence microscopy image of a composite microgel containing both hydrophobic dye Nile Red (compartmentalized in hexadecane nanodroplets) and hydrophilic dye 4, 6-diamidino-2-phenylindole (DAPI) (compartmentalized in poly(N-isopropylacrylamide)). The images were acquired by exciting Nile Red...

Staining with 4,6-diamidino-2-phenylindole (DAPI see Protocol 9.6)... 

---