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Auramine O

Auramine O
IUPAC name bis[4-(dimethylamino)phenyl]methaniminium chloride
CAS number 2465-27-2
SMILES [NH2+]=C (C2=CC=C (N(C)C)C=C2) C1=CC=C(N (C)C)C=C1
Molecular formula C17H22N3Cl
Molar mass 303.8339 g/mol
Melting point

267 °C

R-phrases R22 R24 R40
S-phrases S36/37 S45
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Auramine O, also called Basic yellow 2, Pyocatanium aureum, aizen auramine, Pyoktanin Yellow, Canary Yellow, Pyoktanin, or C.I. 41000, is a diarylmethane dye used as a fluorescent stain. In its pure form, Auramine O appears as yellow needle crystals. It is very soluble in water and soluble in ethanol.

Auramine O can be used to stain acid-fast bacteria (e.g. Mycobacterium), where it binds to the mycolic acid in its cell wall) in a way similar to Ziehl-Neelsen stain.[1] It can also be used as a fluorescent version of Schiff reagent.[2]

Auramine O can be used together with Rhodamine B as the Truant auramine-rhodamine stain for Mycobacterium tuberculosis.[3][4] It can be also used as an antiseptic agent.


  1. ^ Kommareddi S, Abramowsky C, Swinehart G, Hrabak L (1984). "Nontuberculous mycobacterial infections: comparison of the fluorescent auramine-O and Ziehl-Neelsen techniques in tissue diagnosis". Hum Pathol 15 (11): 1085-9. PMID 6208117.
  2. ^ Khavkin T, Kudryavtseva M, Dragunskaya E, Polotsky Y, Kudryavtsev B (1980). "Fluorescent PAS-reaction study of the epithelium of normal rabbit ileum and after challenge with enterotoxigenic Escherichia coli". Gastroenterology 78 (4): 782-90. PMID 6986320.
  3. ^ Truant J, Brett W, Thomas W (1962). "Fluorescence microscopy of tubercle bacilli stained with auramine and rhodamine". Henry Ford Hosp Med Bull 10: 287-96. PMID 13922644.
  4. ^ Arrowood M, Sterling C (1989). "Comparison of conventional staining methods and monoclonal antibody-based methods for Cryptosporidium oocyst detection". J Clin Microbiol 27 (7): 1490-5. PMID 2475523.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Auramine_O". A list of authors is available in Wikipedia.
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