Core Laboratory
10. Free Fatty Acids
Non-esterified fatty acids (NEFA) in serum, when treated with acyl-CoA synthetase (ACS) in the presence of adenosine triphosphate (ATP), magnesium cations and CoA, form the thiol esters of CoA known as acyl-CoA as well as the byproducts adenosine monophosphate (AMP) and pyrophosphate (PPi). In the second portion of the procedure, the acyl-CoA is oxidized by added acyl-CoA oxidase (ACOD) to produce hydrogen peroxide which in the presence of added peroxidase (POD) allows the oxidative condensation of 3-methyl-N-ethyl-N-(b-hydroxyl-ethyl)-aniline (MEHA) with 4-aminoantipyrine to form a purple colored adduct with an absorption maximum at 550nm.
References:
- Duncombe, W.G.: Clin, Chim. Acta 9, 122 (1964)
- Itaya, K. and Ui, M.: J. Lipid Res. 6, 16 (1965)
- Novak, M.: J. Lipid Res. 6, 431 (1965)
- Elphick, M.D.: J. Clin. Pathol. 21, 567 (1968)
- Trout, D.L., Estes, E. H. and Friedberg, S. J.: J. Lipid Res. 1, 199 (1960)
- Dole, V.P., and Meinertz, H.L J. Biol. Chem. 235, 2595 (1960)
Interassay coefficient of variation (CV):
Sample I: CV=2.7% (n=20, Mean=0.33, SD=0.009)
Sample II: CV=1.1% (n=20, Mean=0.62, SD=0.62)
Sample II: CV=1.1% (n=20, Mean=0.99, SD=0.01)
Detection Limit:
5.0 mmol/L
For more information, please contact the Core Laboratory manager or director.