|Aniline oil||3 ml|
|Ethanol (95%)||10 ml|
|HCl (concentrated)||1.5 ml|
|Methylene blue (saturated solution)||30 ml|
|Distilled water to make||100 ml|
Mix aniline oil with ethanol. Slowly add HCl with constant agitation. Add saturated methylene blue solution, dilute to 100 ml with water, and filter.
Original Source: Bacteriological Analytical Manual, 8th Edition, Revision A, 1998.