Solvent Black 3

Chemical Properties

It is a very dark brown to black fine crystalline powder. It is soluble in ethanol, toluene, acetone, and other solvents. In concentrated sulfuric acid, it is violet-black; when diluted, it is dark greenish-blue and produces a blue to black precipitate. The ethanol solution of the dye is bluish-black when concentrated hydrochloric acid is added and dark blue when concentrated sodium hydroxide solution is added.

Uses

Sudan Black is a basic black dye that is used in staining triglycerides and lipids off some lipoproteins. Biological stain. Dyes and metabolites, Environmental Testing.

Definition

ChEBI: Sudan black B is a member of the class of perimidines that is 2,2-dimethyl-2,3-dihydro-1H-perimidine carrying a [4-(phenyldiazenyl)naphthalen-1-yl]diazenyl substituent at position 6. A fat-soluble dye predominantly used for demonstrating triglycerides in frozen sections and for staining of protein bound lipids in paraffin sections. It has a role as a histological dye. It is a member of azobenzenes, a bis(azo) compound and a member of perimidines.

Preparation

aniline diazotization, and Naphthalen-1-amine coupling, and its product to diazotization, and 2,2-Dimethyl-2,3-dihydro-1H-perimidinecoupling.

Biological Activity

Sudan Black B has been used to stain phospholipids and intracellular lipids. Staining pattern is almost similar to myeloperoxidase reaction, with positive staining of granulocytic cells, eosinophils and weak monocytic staining.It doesn′t stain lymphocytes. Sudan Black B can be used to stain older blood or bone marrow smears, but the stain slightly fades over time. It is considered to be a most sensitive and specific reagent for lipid staining. Sudan Black B stains phospholipids gray and neutral fats blue-black.

Safety Profile

A poison by intravenous route. When heated to decomposition it emits toxic vapors of NOx.

Staining Procedures

1 % Sudan black B is dissolved in 70% ethanol, the tissue is stained 1-1.5 h, subsequently washed in 70% ethanol (3 x 15 s), and mounted in 75% glycerol before microscopy. This staining method reveals positive results for lipids.

Properties and Applications

Blue-black. Soluble in ethanol, acetone and toluene. In concentrated sulfuric acid for purple light black, dilution after deep green light blue, blue to black precipitation. Dye ethanol solution to join concentrated hydrochloric acid for blue black; Join concentrated sodium hydroxide solution for skipper.

Standard	Light Fastness	Heat-resistant(℃)		water	Sodium Carbonate(5%)	Hydrochloric acid(5%)
		Melting point	Stable
ISO	General	126	100	Insoluble	No change	No change