acridine orange

**Acridine orange** is a synthetic, cell-permeable, nucleic acid-selective fluorescent cationic dye of the aminoacridine class[2][3][4]. It accumulates preferentially in acidic compartments such as lysosomes, binds nucleic acids (DNA and RNA), and upon excitation emits green or red fluorescence depending on the target[2][3][4]. Acridine orange acts as a DNA intercalator (binds via insertion between base pairs) and associates electrostatically with RNA[4]. It has recently been investigated for **anticancer mechanisms** that exploit its accumulation in acidic cellular compartments of tumors and its photodynamic or radiodynamic activation, which induces cytotoxicity preferentially in tumor cells[1][3][5]. AO affects mitochondrial activity and can induce cell death via mitotoxicity and lysosomal disruption. Its strong fluorescence has made it a widely used tool in fluorescence-guided surgery, imaging, and autophagy/cell cycle research[3][5].

Brand names

acridine orange

Other names

acridine orange baseN3,N3,N6,N6-Tetramethylacridine-3,6-diamineSolvent Orange 15c.i.46005beuchrysineCI 46005CI46005CI-46005C.I.46005:1waxolineorangeaoranzakridinova