Acridine orange

A nucleic acid-selective fluorescent cationic dye

Acridine orange is a nucleic acid-selective fluorescent dye used in various biological and medical applications. It is a cell-permeable, cationic dye that interacts with DNA and RNA, allowing for the visualization of these molecules under a fluorescence microscope.

Chemical properties

Acridine orange is an organic compound with the chemical formula C₁₇H₁₉N₃. It is a member of the acridine family of compounds, characterized by a three-ring structure. The dye exhibits different fluorescence colors depending on its interaction with nucleic acids: it fluoresces green when bound to DNA and red when bound to RNA.

Applications

Acridine orange is widely used in cell biology and microbiology for staining and visualizing nucleic acids. It is particularly useful in:

• Flow cytometry: Acridine orange is used to differentiate between live and dead cells based on their nucleic acid content.
• Microscopy: It is employed in fluorescence microscopy to visualize the structure and function of cells.
• Cancer research: Acridine orange can be used to detect apoptosis and other forms of cell death in cancer cells.
• Microbial identification: It aids in the identification of bacteria and other microorganisms by staining their nucleic acids.

Mechanism of action

Acridine orange intercalates into the nucleic acid strands, inserting itself between the base pairs. This intercalation causes the dye to fluoresce under ultraviolet light. The fluorescence emission is dependent on the type of nucleic acid it binds to, allowing for differentiation between DNA and RNA.

Safety and handling

While acridine orange is a valuable tool in research, it is also a potential mutagen and should be handled with care. Proper laboratory safety protocols should be followed, including the use of personal protective equipment such as gloves and goggles.

Related pages

• Fluorescent dye
• DNA
• RNA
• Microscopy

Gallery

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  Chemical structure of acridine orange
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  3D ball model of acridine orange

Acridine orange

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