Purpose

Lipids and fatty acids serve several fundamental physiological roles in nature including the formation of lipid bilayers, as energy substrate and as precursors of eicosanoids. Fatty acid analysis can identify trends in essential fatty acid status that may signify aberrations in physiology and or cell culture systems. Fatty acids in a variety of matrices are quantified using gas chromatography. This method is for the accurate determination and quantification of total phospholipids, free or non-esterified fatty acids, triglycerides, and cholesterol esters.

Summary

Fatty acids and lipids are analyzed by classical methods in lipid chemistry. Cells, tissue, plasma, and cell culture media is extracted with a nonpolar solvent like chloroform with methods like Bligh and Dyer and/or Folch and Lees. Once lipid extracts are generated, they can then be separated by thin-layer chromatography to fraction the lipid extract and subsequently tested for total phospholipids, free or non-esterified fatty acids, triglycerides, and cholesterol esters.

The fractioned lipid extracts are quantified with gas chromatography. Quantification is based on the recovery of odd chain internal standards.

Profiles Offered

Total Phospholipids

Total phospholipids analysis determines the essential fatty acid (omega 3 and omega 6) content of a membrane (cells) or serum (as lipoprotein). Total phospholipids analysis reports the quantities of phospholipids and their subsequent fatty acid composition.

Free Fatty Acid Analysis

Free or non-esterified fatty acid analysis determines relative amounts of unbound or unesterified levels of fatty acids. The free fatty acids that are quantified are common mammalian fatty acids from 14 to 24 carbons.

Triglyceride Analysis

Triglycerides are the predominant storage lipid with 3 fatty acids acylated to a glycerol backbone. Determination of triglyceride content is typically done for plasma or serum samples.

Cholesterol esters

Cholesterol esters are cholesterol with a fatty acid esterified to its structure. Cholesterol ester fatty acid content is often of interest for plasma or serum based samples.