Is Oil Red O vegan?

Oil Red O

Vegan

Oil Red O is a lysochrome (fat-soluble) diazo dye used for staining neutral triglycerides and lipids on frozen sections and some lipoproteins on paraffin sections. It appears as a red powder with an absorbance maximum at 518 nm. It is a synthetic organic compound with no animal-derived components.

Also known as Solvent Red 27, Sudan red 5B, Sudan Red 5B
CAS number 1320-06-5
CI number CI 26125
Last reviewed 3 June 2026

Sources

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