A spectrophotometric method for the determination of free and esterified carnitine

We have developed a spectrophotometric assay to measure carnitine in any tissue. The test is based on the transformation of carnitine to acetyl-carnitine catalyzed by carnitine acetyltransferase. The second reaction product, reduced Coenzyme A, is converted to succinoyl-CoA by adding 2-oxoglutarate. The enzyme which catalyzes this reaction, 2-oxoglutarate dehydrogenase, reduces NAD which is followed spectrophotometrically. Via external standards the carnitine concentration can be determined. In a detailed study we proved the reproducibility, precision and specificity of the assay and its correspondence with the radiochemical test.