DAPI Staining Solution

DAPI (4 ', 6-diamidino-2-phenylindole, 4', 6-Diamidino-2-phenylindole) is a blue fluorescent dye that can penetrate cell membranes. The planar aromatic ring structure of DAPI molecules complements the A-T base pair enrichment region of DNA, allowing DAPI molecules to embed between the base pairs of DNA double strands. When DAPI is not bound to DNA, its molecule is in a free state and hardly fluoresces. When DAPI binds to DNA, the molecular conformation changes, and under UV excitation, it can emit strong blue fluorescence (maximum excitation wavelength of about 340 nm, emission wavelength of about 488 nm). DAPI has high affinity for double stranded DNA and can specifically label cell nuclei.