Abstract: A mass spectrometry method comprises: isolating a first portion of a selected primary ion species; generating one or more fragment ion species by fragmenting the isolated first portion of the primary ion species; determining mass-to-charge (m/z) values of the fragment ion species; searching a mass spectral database or a mass spectral library for a compound for which a predicted or observed m/z value of a primary ion species matches the selected primary ion species and for which one or more m/z values of fragment ion species that are predicted or observed to be generated by fragmentation of the matched primary ion species m/z value match determined fragment-ion m/z values; determining a measure of success of the search; and causing a mass spectrometer to perform one or more altered or replacement procedures that override pre-planned default procedures based on the determined measure of success.

Abstract: Real-time search (RTS) for mass spectrometry is described. In one instance, precursor ions generated from a sample are introduced into a mass spectrometer during an introduction period. The precursor ions are fragmented to form product ions, and a mass spectrum is acquired. During the introduction period, scores indicating the similarity between the mass spectrum and a candidate mass spectrum are identified. Based on the distribution of the scores, an action is performed.

Abstract: A method is described that involves simplification of UVPD mass spectra and comprises selecting precursor ions for UVPD fragmentation, performing UVPD fragmentation on selected precursor ions to give UVPD fragment ions. PTR may then be performed on the UVPD fragment ions with optional ion parking to yield charge-state reduced UVPD fragment ions. The UVPD-PTR steps may be repeated above n times where n=1 to 50. Ion parking may enhance the intensity of selected lower fragment ion charge states or to increase the intensity of peaks in selected m/z ranges. After a number of PTR-UVPD iterations, fragment ions are mass analyzed. The method provides a way of simplifying UVPD mass spectral product ions by lowering fragment ion charge states and spreading out resulting product ions in m/z mass spectral space when compared to using UVPD fragmentation alone.

Abstract: A method is described that involves simplification of UVPD mass spectra and comprises selecting precursor ions for UVPD fragmentation, performing UVPD fragmentation on selected precursor ions to give UVPD fragment ions. PTR may then be performed on the UVPD fragment ions with optional ion parking to yield charge-state reduced UVPD fragment ions. The UVPD-PTR steps may be repeated above n times where n=1 to 50. Ion parking may enhance the intensity of selected lower fragment ion charge states or to increase the intensity of peaks in selected m/z ranges. After a number of PTR-UVPD iterations, fragment ions are mass analyzed. The method provides a way of simplifying UVPD mass spectral product ions by lowering fragment ion charge states and spreading out resulting product ions in m/z mass spectral space when compared to using UVPD fragmentation alone.

Abstract: One embodiment of the present invention provides a method of testing for compounds which may induce STF-1 transcription. Pancreatic islet cells which express the STF-1/lacz fusion gene are isolated and the effect of various compounds on STF-1 expression is measured by adding the compound of interest to STF-1/lacZ expressing cells. LacZ activity in control and treated cells is then quantitated by a colorimetric assay. Using this method, a large number of compounds can be screened and STF-1 inducing compounds can be identified readily. Another embodiment of the present invention provides a method of using the STF-1 promoter to mark insulin producing pancreatic islet cells in vivo. In this regard, the green fluorescent protein (GFP) served as an indicator. The introduction of the STF-1 green fluorescent protein transgene into pigs allows for the efficient and rapid recovery of insulin producing cells from the pancreas.