Related: Biological Science MOC
TLDR
A fluroescent dye that binds with DNA or RNA, used in fluorescent microscopy and flow cytometry.
Staining procedure for flow cytrometry includes different buffer preparations, and it’s used mostly to confirm presence of bacteria in positive blood cultures as a “double check” if there’s still doubt after gram staining.
Some other applications include:
- For enumerating the microbial load in a sample since acridine orange binds with the nucleic acid of both living and dead bacteria.
- Detection of cell wall-deficient bacteria (e.g., mycoplasmas) grown in cultures. Cell wall deficient bacteria are hard to visualize in Gram stain as they cannot retain Gram stain dyes.
- For differential staining of human cells and prokaryotic cell with a fluorescence microscope. Human cells are stained black to faint green iso that bright orange organisms are easily detected.
- Acridine orange is also used in a method referred to as the quantitative buffy coat (QBC), a rapid screening tool for the detection of malaria.
- For analyzing mitochondria and lysosomal content by flow cytometry.
- For visual detection of nucleic acids on agarose and polyacrylamide gels.
- For identifying engulfed apoptotic cells because they will fluoresce upon engulfment.