Abstract: A method, a labeling reagent, sets of labeling reagents, and labeling techniques are provided for the analysis of ketosterol biomarkers such as bile acid precursors from human plasma, serum or whole blood. This method is used for new born screening for Cerebrotendinous Xanthomatosis (CTX). Methods for labeling, analyzing, and quantifying ketosterol biomarkers are also disclosed as are methods that also use mass spectrometry.

Abstract: A method, a labeling reagent, sets of labeling reagents, and labeling techniques are provided for the analysis of ketosterol biomarkers such as bile acid precursors from human plasma, serum or whole blood. This method is used for new born screening for Cerebrotendinous Xanthomatosis (CTX). Methods for labeling, analyzing, and quantifying ketosterol biomarkers are also disclosed as are methods that also use mass spectrometry.

Abstract: Embodiments of the present invention provide for detecting and/or screening for conditions associated with altered sterols by derivatization of sterols to provide suitable sensitivity and selectivity of detection using tandem mass spectrometry with electrospray ionization. Such testing may be performed to detect and/or screen for conditions such as Smith-Lemli-Opitz syndrome, familial hypercholesterolaemia, and cerebrotendinous xanthomatosis, or certain bile acid disorders.

Abstract: Embodiments of the present invention provide for detecting and/or screening for conditions associated with altered sterols by dehvatization of sterols to provide suitable sensitivity and selectivity of detection using tandem mass spectrometry with electrospray ionization. Such testing may be performed to detect and/or screen for conditions such as Smith-Lemli-Opitz syndrome, familial hypercholesterolemia, and cerebrotendinous xanthomatosis, or certain bile acid disorders.

Abstract: The invention relates to the discovery that a putative gene of Mycobacterium tuberculosis with no previously identified function is responsible for the ability of the bacterium to activate thioamide drugs. Since M. tuberculosis has a low rate of synonymous mutations, all mutations in this gene, identified as Rv3854c and now termed “EtaA,” are expected to inhibit the ability of a bacterium with the mutation to activate a thioamide or thiocarbonyl drug. Thus, detecting a bacterium with a mutation in this gene indicates that the bacterium is resistant to treatment with thioamides.