Abstract:
Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.
Abstract:
The invention relates to the detection of vitamin D metabolites. In a particular aspect, the invention relates to methods for detecting derivatized vitamin D metabolites by mass spectrometry.
Abstract:
Provided are methods for measuring renin activity in a plasma sample using mass spectrometry. The methods generally involve ionizing purified angiotensin 1 from the sample and detecting the amount of angiotensin 1 ions generated. The amount of detected angiotensin 1 ions are then related to the amount of angiotensin 1 generated in the sample, which in turn is related to renin activity in the sample.
Abstract:
Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.
Abstract:
Provided are methods of detecting the presence or amount of a dihydroxyvitamin in D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a dihydroxyvitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. In certain preferred embodiments the methods include immunopurifying the dihydroxyvitamin D metabolites prior to mass spectrometry. Also provided are methods to detect the presence or amount of two or more dihydroxyvitamin D metabolites in a single assay.
Abstract:
Provided are methods for determining the presence or amount of testosterone in a test sample, comprising ionizing all or a portion of the testosterone present in the sample to produce one or more testosterone ions that are detectable in a mass spectrometer. All or a portion of the testosterone present in the sample is ionized to produce one or more testosterone ions, which may be isolated and fragmented to produce precursor ions. A separately detectable internal testosterone standard can be provided in the sample. In a preferred embodiment, the reference is 2,2,4,6,6-d5 testosterone.
Abstract:
Provided are methods for measuring renin activity in a plasma sample using mass spectrometry. The methods generally involve ionizing purified angiotensin 1 from the sample and detecting the amount of angiotensin 1 ions generated. The amount of detected angiotensin 1 ions are then related to the amount of angiotensin 1 generated in the sample, which in turn is related to renin activity in the sample.
Abstract:
Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a vitamin D metabolite in a sample and detecting the amount of the ion to determine the presence or amount of the vitamin D metabolite in the sample. Also provided are methods to detect the presence or amount of two or more vitamin D metabolites in a single assay.
Abstract:
Provided are methods for determining the amount of estrone in a sample using mass spectrometry. The methods generally involve ionizing estrone in a sample and detecting and quantifying the amount of the ion to determine the amount of estrone in the sample.
Abstract:
Methods are described for measuring the amount of a kisspeptin-54-derived peptides in a sample. More specifically, mass spectrometric methods are described for detecting and quantifying a kisspeptin-54 derived peptides in a sample utilizing on-line extraction methods coupled with tandem mass spectrometric techniques.