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.

The invention relates to the detection of fatty acids. In a particular aspect, the invention relates to methods for detecting very long chain fatty acids and branched chain fatty acids by mass spectrometry.

Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to 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.

The present invention comprises a method for identifying the presence or absence of a pulmonary embolism using a combination of tests and brightline thresholds. The first test is a blood based test measuring D-Dimer concentration and the second test is a respiratory analysis that determines a carboximetry ratio. If the measured D-Dimer value is at or above a threshold indicative of concern and the carboximetry value is equal to or less than a carboximetry ratio threshold, pulmonary embolism is present. If the measured D-Dimer value is at or above a threshold indicative of concern and the respiratory analysis yields a carboximetry ratio greater than the carboximetry ratio threshold, test results are inconclusive and additional testing is required to determine whether a pulmonary embolism is present.

The invention relates to the detection of fatty acids. In a particular aspect, the invention relates to methods for detecting very long chain fatty acids and branched chain fatty acids by mass spectrometry.

Provided are methods of detecting the presence or amount of a vitamin D metabolite in a sample using mass spectrometry. The methods generally directed to 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.

A molecularly imprinted polymer sensor for sensing a target molecule includes (a) a porous polymer film that is molecularly imprinted with a homolog of the target molecule and includes a conductive polymer having resistance sensitive to binding with the target molecule and a structural polymer providing porosity to the polymer film, and (b) interdigitated electrodes, located on a surface of the polymer film, for measuring a change in the resistance to sense said binding.

The present invention comprises a method for identifying the presence or absence of a pulmonary embolism using a combination of tests and brightline thresholds. The first test is a blood based test measuring D-Dimer concentration and the second test is a respiratory analysis that determines a carboximetry ratio. If the measured D-Dimer value is at or above a threshold indicative of concern and the carboximetry value is equal to or less than a carboximetry ratio threshold, pulmonary embolism is present. If the measured D-Dimer value is at or above a threshold indicative of concern and the respiratory analysis yields a carboximetry ratio greater than the carboximetry ratio threshold, test results are inconclusive and additional testing is required to determine whether a pulmonary embolism is present.

Methods for determining the amount of vitamin D compounds in a sample are provided. The methods can employ LC-MS/MS techniques and optionally the use of deuterated internal standards. Methods for diagnosing vitamin D deficiencies are also provided.

Provided are methods of detecting the presence or amount of a dihydroxyvitamin D metabolite in a sample using mass spectrometry. The methods generally comprise ionizing a dihydorxyvitamin 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.