Abstract: A method for determining the amount of chromogranin A (CgA) in a sample includes: (a) purifying CgA in the sample; (b) adding an internal standard; (c) ionizing CgA and the internal standard to produce one or more CgA ion(s) and one or more internal standard ion(s) detectable by mass spectrometry; (d) determining the amount of the ion(s) from step (c) by mass spectrometry; and (e) correlating the amount of CgA in the sample to the amount of ion(s) measured in step (d).

Abstract: Provided are methods for detecting chromogranin A by mass spectrometry. In another aspect, provided herein are methods for quantitating chromogranin A by mass spectrometry. In another aspect, provided herein are methods for prognosis of or measuring the size of neuroendocrine tumors by mass spectrometry.

Abstract: Provided are methods for detecting chromogranin A by mass spectrometry. In another aspect, provided herein are methods for quantitating chromogranin A by mass spectrometry. In another aspect, provided herein are methods for prognosis of or measuring the size of neuroendocrine tumors by mass spectrometry.

Abstract: Provided are methods for detecting chromogranin A by mass spectrometry. In another aspect, provided herein are methods for quantitating chromogranin A by mass spectrometry. In another aspect, provided herein are methods for prognosis of or measuring the size of neuroendocrine tumors by mass spectrometry.

Abstract: The present invention relates to compositions and methods for analyzing analytes of interest in liquid samples by mass spectrometry, and preferably in patient samples. Preferred analytes of interest include sirolimus (rapamycin), corticosteroids, bile acids and lamotrigine (lamictal). In one embodiment, by careful selection of target ions, a number of corticosteroids can be analyzed simultaneously and without interference from closely related molecules. In another embodiment, the present methods combine high turbulence liquid chromatography with mass spectrometry performed in positive and negative mode in a single assay to enable the detection and quantification of the composit˜on of bile acid pools. By combining mass spectrometry and high-throughput chromatography, the methods and compositions described herein can provide a rapid, sensitive, and accurate assay for use in large clinical laboratories.