The addition of acridine orange to a faecal concentrate highlights the chromidial bars of Entamoeba coli, Entamoeba histolytica/ dispar and Entamoeba hartmanni, which fluoresce bright green.
Stock acridine orange – 1 ml
Glacial acetic acid – 0.5 ml
Buffered water pH 6.8 – 8.5 ml
Add an equal volume of stain to the concentrate. Examine the deposit under UV light after 30 minutes.