Abstract: Methods are described for monitoring the amounts of PTH variants in a biological sample by digesting the sample to produce surrogate peptides specific to the targeted PTH variants, and detecting and quantifying the surrogate peptides by selective reaction monitoring (SRM) mass spectrometry, using a set of precursor-to-product ion transitions optimized for sensitivity and selectivity. The PTH variants, or a portion thereof, may be concentrated in the sample by means of immunoaffinity capture or other suitable technique. The mass spectrometric method described herein enables the concurrent measurement of peptides representative of a plurality of targeted PTH variants in a single assay.

Abstract: Methods are described for monitoring the amounts of PTH variants in a biological sample by digesting the sample to produce surrogate peptides specific to the targeted PTH variants, and detecting and quantifying the surrogate peptides by selective reaction monitoring (SRM) mass spectrometry, using a set of precursor-to-product ion transitions optimized for sensitivity and selectivity. The PTH variants, or a portion thereof, may be concentrated in the sample by means of immunoaffinity capture or other suitable technique. The mass spectrometric method described herein enables the concurrent measurement of peptides representative of a plurality of targeted PTH variants in a single assay.

Abstract: Methods are disclosed for rapidly and reliably differentiating between ischemic and hemorrhagic stroke events in a human patient. The methods include obtaining a biological sample, such as blood serum, and analyzing the sample or a derivative thereof by mass spectrometry to measure the amount of one or more targeted proteins differentially present and ischemic and hemorrhagic stroke patients. The analysis may include proteolytic digestion of the biological sample and selective reaction monitoring (SRM) tandem mass spectrometry of the digested sample to determine the amounts of surrogate peptides corresponding to the targeted proteins.

Abstract: Methods are described for monitoring the amounts of PTH variants in a biological sample by digesting the sample to produce surrogate peptides specific to the targeted PTH variants, and detecting and quantifying the surrogate peptides by selective reaction monitoring (SRM) mass spectrometry, using a set of precursor-to-product ion transitions optimized for sensitivity and selectivity. The PTH variants, or a portion thereof, may be concentrated in the sample by means of immunoaffinity capture or other suitable technique. The mass spectrometric method described herein enables the concurrent measurement of peptides representative of a plurality of targeted PTH variants in a single assay.

Abstract: The present invention relates to biomarkers in maternal serum samples and methods for predicting whether a fetus has Trisomy 21 during the first trimester of pregnancy based on the differential expression of a combination, or subcombination, of the same.