World Library  
Flag as Inappropriate
Email this Article

Oil Red O

Article Id: WHEBN0003191608
Reproduction Date:

Title: Oil Red O  
Author: World Heritage Encyclopedia
Language: English
Subject: Sudan stain, Sudan Black B, Adipogenesis, Solvent dyes, Stains
Publisher: World Heritage Encyclopedia

Oil Red O

Oil Red O
IUPAC name
1-(2,5-dimethyl-4-(2,5-dimethylphenyl) phenyldiazenyl) azonapthalen-2-ol
ChemSpider  Y
Jmol-3D images Image
Molar mass 408.49496
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 Y  (: Y/N?)

Oil Red O (Solvent Red 27, Sudan Red 5B, C.I. 26125, C26H24N4O) is a lysochrome (fat-soluble dye) diazo dye used for staining of neutral triglycerides and lipids on frozen sections and some lipoproteins on paraffin sections. It has the appearance of a red powder with maximum absorption at 518 (359)nm.


  • Uses 1
  • Forensic 2
  • References 3
  • External links 4


Oil Red O is one of the dyes used for Sudan staining. Similar dyes include Sudan III, Sudan IV, and Sudan Black B. The staining has to be performed on fresh samples, as alcohol fixation removes most lipids.

Oil Red O largely replaced Sudan III and Sudan IV, as it provides much deeper red color and the stains are therefore much easier to see.

In pyrotechnics, Oil Red O is used in some compositions of red colored smokes. It is also used for making dyes.


When staining, Oil Red O can make fat more visible in various cuts in pathology.[1]

It is also used in a technique (the method is called as the dye: Oil Red O), discovered in 2004 by Alexandre Beaudoin, for staining latent fingerprints.[2] This technique allows the development of latent fingerprints on porous exhibits (such as paper, cardboard, etc.) that are dry or wet.

It mainly targets fat deposits on the surface of porous exhibits.[3] It is a non-destructive technique (which does not destroy the exhibit and doesn’t prevent the use of other techniques).

It is a safe alternative to the Physical Developer method,[4] and is also used in sequence with other methods of fingerprints development.[5]


  1. ^ "Forensic Pathology". 
  2. ^ Triplett M, Fingerprint Dictionary, Two Rings Publishing, Bellevue, Washington.
  3. ^ Beaudoin, A. New technique for revealing latent fingerprints on wet, porous surfaces: Oil Red O. Journal of Forensic Identification, 2004, 54 (4), 413-421.
  4. ^ Rawji, A. ; Beaudoin, A. Oil Red O versus Physical Developer on wet papers: a comparative study. Journal of Forensic Identification, 2006, 56 (1), 33-54.
  5. ^ Guigui, K.; Beaudoin, A. The use of Oil Red O in sequence with other methods of fingerprint development. Journal of Forensic Identification, 2007, 57 (4), 550-581.

External links

  • Stains File entry
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from Project Gutenberg are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.