Sudan Black B

Sudan Black B (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 dark brown to black powder with maximum absorption at 596-605 nm and melting point 120-124 °C. It stains blue-black.

Sudan Black B is one of the dyes used for Sudan staining. Similar dyes include Oil Red O, Sudan III, and Sudan IV.

Sudan Black B can be used to stain some other materials than the other Sudan dyes, as it is not so specific to lipids.

A use of Sudan Black B is in fingerprint enhancement. It is useful for detecting fats that are contaminated with oil and grease.

Its other names are Sudan Black, Fat Black HB, Solvent Black 3, and C.I. 26150.