, 2-(4-Carbamimidoylphenyl)indole-6-carboximidamide Dihydrochloride
4',6'-Diamidino-2-phenylindole dihydrochloride (DAPI dihydrochloride) used in nuclear staining
4',6'-Diamidino-2-phenylindole dihydrochloride (DAPI dihydrochloride)
DAPI (4′,6-Diamidino-2-Phenylindole, dihydrochloride) is a popular blue DNA dye that is used as a nuclear counterstain in fluorescence microscopy, chromosome staining and flow cytometry. The dye binds to the minor groove of dsDNA with approximately 20-fold fluorescence enhancement, with higher affinity for A-T rich regions. Also see DAPI dilactate (catalog no. 40009), a more water soluble form of the dye.
- Classic blue nuclear counterstain for fixed cells
- Can be used at higher concentrations to stain live cells
- λEx/λEm (with DNA) = 358/461 nm
- Off-white solid soluble in H2O
- Store at 4°C and protect from light, especially in solution
DAPI can be used to stain live bacteria (gram-positive and gram-negative) but in live yeast the staining is weak and not nuclear.