Staining of lipids

• Simple lipid


  esters of fatty acids with alcohols and are usually found in the body as energy stores in adipose tissue
• Compound lipids


  onsist of a fatty acid, an alcohol and one or more other groups such as phosphorus or nitrogen.
• Phospholipids


  important components of cellular membranes particularly found in mitochondria and nervous tissue elements and are readily stained by Sudan Black B and acid hematin.
• Glycolipids


  composed of fatty acids and hexoses, possessing characteristics of both lipids and carbohydrates and are therefore stained by Sudan Black B and PAS techniques.
• Derived lipids


  fatty acids that are derived from hydrolysis of simple and compound lipids. Examples are cholesterol, bile acids, sex hormones and adrenocortical hormones.
• White adipose tissue (WAT)

  largely composed of unilocular lipid-filled adipocytes that specialize in lipid storag
• brown adipose tissue (BAT)


  largely composed of multilocular adipocytes that specialize in lipid burning.
• signet rings

  Fat cells appear as on H&E stains
• Lipochrome (lipofuscin)

  pigments are the breakdown products within cells from oxidation of lipids and lipoproteins.
• Lipochrome (lipofuscin)

  wear-and-tear pigments found most commonly in heart, liver, CNS, and adrenal cortex.
• Sudanophilia is the property of tissues to be stained with fat or oil-soluble dyes, regardless of the type of dye used, due to their essential lipid nature.
• Sudan Black B

  most sensitive lipid stain known
• Sudan IV (Scharlach B)

  staining fats with a more brilliant or deeper red color than Sudan III which stains lipids orange-red
• Sudan III


  predominantly used for staining triglycerides in animal tissues (frozen sections)
• Sudan Black BB

  -stains phospholipids as well as neutral fats

  -does not stain crystalline cholesterol, and free fatty acids tend to be dissolved in the alcoholic dye bath.
• Oil Red O


  used to demonstrate the presence of fat or lipids in fresh, frozen tissue sections.
• Scharlach R or with Oil Red O

  stains neutral fats and lipofuscin well
• Sudan Black Method for Lipids

  Lipids - blue black

  Nuclei - Red
• Sudan IV (Scharlach R) Stain for Lipids

  Lipids (mainly triglycerides) - red

  Nuclei - blue/black
• Scharlach R (Sudan IV) is the most commonly used stain, producing a rapid and permanent coloration of lipid. The addition of benzoic acid to the staining solution materially intensifies the resulting color and prevents deterioration. True fats stain intensely while cholesterol stains less intensely.
• Oil Red 0 Method in Dextrin

  Lipid - red

  Nuclei - blue
• Osmic Acid Stain for Fat

  Fats - black

  Nuclei - yellow-orange
• Nile Blue Sulfate Method for Fats

  capable of differentiating two lipid classes simultaneously by the action of its two components: a red oxazone which dissolves neutral lipids, and a blue oxazine which is basic and reacts with phospholipids and free fatty acids.
• Free Fatty Acids

  can then be stained with Weigert's lithium hematoxylin, dimethylaminobenzidine rhodamine, or rubeanic acid.
• can be demonstrated as cholesterol after hydrolysis by cholesterol ester hydrolase and has also been detected with the use of enzyme cholesterol esterase
• The sulfate esters of cerebrosides (sulfatides) are generally deposited in brain and other organs of patients with sulfatide storage disease known as metachromatic leukodystrophy
• Gangliosides

  The stored gangliosides are

  PAS (+)

  Sudanophilic (+)

  Luxol fast blue (+)