Patent ID: 8318417

Claim:
A multiplex method for one or more metabolic analytes and activity of one or more metabolically indicative enzymes in a biological sample from an individual, comprising: (a) contacting the sample with one or more natural substrates for one or more metabolically indicative enzymes and with one or more protease inhibitors to produce a reaction admixture, the one or more metabolically indicative enzymes characterized in that increased or decreased activity of the one or more metabolically indicative enzymes in the sample compared to a normal reference activity of the one or more metabolically indicative enzymes is associated with one or more metabolic disorders selected from an aminoacidopathy, a fatty acid oxidation disorder, an organic acid disorder, and a lysosomal storage disorder; (b) reacting the reaction admixture under conditions wherein the one or more metabolically indicative enzymes is capable of acting on the one or more natural substrates to generate at least one product which is a first metabolic indicator to be assayed; (c) contacting the reaction admixture with a chaotrope that inhibits the ability of the one or more metabolically indicative enzymes to act on the one or more natural substrates, wherein the at least one product and the one or more metabolic analytes are soluble in the chaotrope, to produce a test sample, wherein the one or more metabolic analytes is a second metabolic indicator to be assayed and the second metabolic indicator is selected from an amino acid and a carnitine, the second metabolic indicator characterized in that increased or decreased level of the second metabolic indicator in the sample compared to a normal reference level of the second metabolic indicator is associated with one or more metabolic disorders selected from an aminoacidopathy, a fatty acid oxidation disorder, an organic acid disorder, and a lysosomal storage disorder; and (d) determining the amount of the first and second metabolic indicators in the test sample simultaneously in a single vessel, without purification of the first and second metabolic indicators away from other components of the test sample, using mass spectrometry.