This method is designed to assess the potential of a test material to induce lipid breakdown in cultured human subcutaneous adipocytes.  Adipocytes store fatty acids in the form of triglycerides.  When stimulated with appropriate stimuli (i.e. isoproterenol) the triglycerides are broken down into free fatty acids and glycerol and both of these components are released into the culture media.  The released glycerol can then be easily measured via the following series of enzymatic reactions: 

Glycerol + ATP	Glycerol Kinase	Glycerol-1-Phosphate + ADP
Glycerol-1-Phosphate + O2	Glycerol Phosphate Oxidase	Dihydroxyacetone Phosphate + H2O2
H2O2 + 4-aminoantipyrine + sodium N-ethyl-N-(3-sulfopropyl) m-anisidine (colorless)	Peroxidase	Quinoneimine Dye (absorbs at 540 nm)

 The amount of quinoneimine dye formed is proportional to the amount of glycerol in the sample, thus as the amount of lipolysis increases there will be more of the colored end product formed.