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: Methods are described for determining the amount of insulin in a sample. Provided herein are mass spectrometric methods for detecting and quantifying insulin and C-peptide in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques. Also provided herein are mass spectrometric methods for detecting and quantifying insulin and b-chain in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques.

Abstract: Methods are described for determining the amount of insulin in a sample. Provided herein are mass spectrometric methods for detecting and quantifying insulin and C-peptide in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques. Also provided herein are mass spectrometric methods for detecting and quantifying insulin and b-chain in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques.

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: Methods are described for determining the amount of insulin in a sample. Provided herein are mass spectrometric methods for detecting and quantifying insulin and C-peptide in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques. Also provided herein are mass spectrometric methods for detecting and quantifying insulin and b-chain in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric technique.

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: Methods are described for determining the amount of insulin in a sample. Provided herein are mass spectrometric methods for detecting and quantifying insulin and C-peptide in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques. Also provided herein are mass spectrometric methods for detecting and quantifying insulin and b-chain in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques.

Abstract: Methods are described for determining the amount of insulin in a sample. Provided herein are mass spectrometric methods for detecting and quantifying insulin and C-peptide in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques. Also provided herein are mass spectrometric methods for detecting and quantifying insulin and b-chain in a biological sample utilizing enrichment and/or purification methods coupled with tandem mass spectrometric or high resolution/high accuracy mass spectrometric techniques.